7- and 9- carbamate, urea, thiourea, thiocarbamate, and heteroaryl-amino substituted tetracycline compounds

ABSTRACT

Substituted tetracycline compounds, methods of synthesis, and methods of use are discussed. Tetracyclines useful for treating tetracycline related disorders are also discussed. Intermediates useful for synthesizing other tetracycline compounds are also included.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.09/823,884, filed Mar. 30, 2001, now U.S. Pat. No. 6,818,634 whichclaims the benefit of U.S. Provisional Application No. 60/280,367, filedMar. 29, 2001; U.S. Provisional Application No. 60/193,972, filed Mar.31, 2000; and U.S. Provisional Application No. 60/193,879, filed Mar.31, 2000. The entire contents of all of the aforementioned applicationsare hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The development of the tetracycline antibiotics was the direct result ofa systematic screening of soil specimens collected from many parts ofthe world for evidence of microorganisms capable of producingbacteriocidal and/or bacteriostatic compositions. The first of thesenovel compounds was introduced in 1948 under the name chlortetracycline.Two years later, oxytetracycline became available. The elucidation ofthe chemical structure of these compounds confirmed their similarity andfurnished the analytical basis for the production of a third member ofthis group in 1952, tetracycline. A new family of tetracyclinecompounds, without the ring-attached methyl group present in earliertetracyclines, was prepared in 1957 and became publicly available in1967.

Recently, research efforts have focused on developing new tetracyclineantibiotic compositions effective under varying therapeutic conditionsand routes of administration. New tetracycline analogues have also beeninvestigated which may prove to be equal to or more effective than theoriginally introduced tetracycline compounds. Examples include U.S. Pat.Nos. 3,957,980; 3,674,859; 2,980,584; 2,990,331; 3,062,717; 3,557,280;4,018,889; 4,024,272; 4,126,680; 3,454,697; and 3,165,531. These patentsare representative of the range of pharmaceutically active tetracyclineand tetracycline analogue compositions.

Historically, soon after their initial development and introduction, thetetracyclines were found to be highly effective pharmacologicallyagainst rickettsiae; a number of gram-positive and gram-negativebacteria; and the agents responsible for lymphogranuloma venereum,inclusion conjunctivitis, and psittacosis. Hence, tetracyclines becameknown as “broad spectrum” antibiotics. With the subsequent establishmentof their in vitro antimicrobial activity, effectiveness in experimentalinfections, and pharmacological properties, the tetracyclines as a classrapidly became widely used for therapeutic purposes. However, thiswidespread use of tetracyclines for both major and minor illnesses anddiseases led directly to the emergence of resistance to theseantibiotics even among highly susceptible bacterial species bothcommensal and pathogenic (e.g., pneumococci and Salmonella). The rise oftetracycline-resistant organisms has resulted in a general decline inuse of tetracyclines and tetracycline analogue compositions asantibiotics of choice.

SUMMARY OF THE INVENTION

The invention pertains, at least in part, to substituted tetracyclinecompounds of the formula (I):

wherein:

-   -   X is CHC(R¹³Y′Y), CR^(6′)R⁶, S, NR⁶, or O;    -   R² is hydrogen, alkyl, alkynyl, alkoxy, alkylthio,        alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic or a prodrug moiety;    -   R⁴ and R^(4′) are each hydrogen, alkyl, alkenyl, alkynyl,        alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,        arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrug        moiety;    -   R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug        moiety;    -   R⁵ is hydrogen, hydroxyl, or a prodrug moiety;    -   R⁶, R^(6′), and R⁸ are each independently hydrogen, alkyl,        alkenyl, alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl,        alkylsulfonyl, alkylamino, arylalkyl, or halogen;    -   R⁷ is hydrogen, dialkylamino, heteroaryl-amino, or        NR^(7c)C(═W′)WR^(7a);    -   R¹³ is hydrogen, hydroxy, alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   Y′ and Y are each independently hydrogen, halogen, hydroxyl,        cyano, sulfhydryl, amino, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or        arylalkyl;    -   R⁹ is hydrogen, heteroaryl-amino, or NR^(9c)C(═Z′)ZR^(9a);    -   Z is CR^(9d)R^(9c), NR^(9b), or O;    -   Z′ is O or S;    -   R^(9a), R^(9b), R^(9c), R^(9d), and R^(9e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, alkylsulfonyl, arylsulfonyl,        alkoxycarbonyl, arylcarbonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic, absent, or a prodrug moiety, and        R^(9d) and R^(9e) may be linked to form a ring;    -   W is CR^(7d)R^(7e), NR^(7b) or O;    -   W′ is O or S; and    -   R^(7a), R^(7b), R^(7c), R^(7d), and R^(7e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, arylsulfonyl, alkoxycarbonyl,        arylcarbonyl, alkylamino, arylalkyl, aryl, heterocyclic,        heteroaromatic, absent, or a prodrug moiety, and R^(7d) and        R^(7e) may be linked to form a ring;    -   and pharmaceutically acceptable salts thereof, provided that R⁹        is not hydrogen when R⁷ is dialkylamino or hydrogen.

The invention also pertains, at least in part, to methods for treating atetracycline responsive state in a subject. The method includesadministering to the subject a substituted tetracycline compound offormula (I).

In another embodiment, the invention includes pharmaceuticalcompositions comprising a therapeutically effective amount of asubstituted tetracycline compound of formula (I) and a pharmaceuticallyacceptable carrier.

In yet another embodiment, the invention pertains to a method forsynthesizing 7- and/or 9-substituted tetracycline compounds. The methodincludes contacting a tetracycline compound with a nitrating agent,under conditions such that a nitro tetracycline compound is formed,contacting the nitro tetracycline compound with a hydrogenating agent,under conditions such that an amino tetracycline compound is formed, andcontacting the amino tetracycline compound with an amino reactivesubstrate, such that a 9- or 7-substituted tetracycline compound isformed.

The invention also pertains, at least in part, to a method forsynthesizing a 7- and/or 9-substituted tetracycline compound of formula(I), by contacting a reactive intermediate with appropriate reagentsunder appropriate conditions, such that a substituted tetracyclinecompound of formula (I) is formed.

The reactive intermediate, wherein said reactive intermediate is of theformula:

wherein:

-   -   X is CHC(R¹³Y′Y), CHR⁶, S, NR⁶, or O;    -   R² is hydrogen, alkyl, alkynyl, alkoxy, alkylthio,        alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl,        heterocyclic, hetetroaromatic or a prodrug moiety;    -   R⁴ and R^(4′) are each hydrogen, alkyl, alkenyl, alkynyl,        alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,        arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrug        moiety;    -   R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug        moiety;    -   R⁵ is hydrogen, hydroxyl, or a prodrug moiety;    -   R⁶ and R⁸ are each independently hydrogen, alkyl, alkenyl,        alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,        alkylamino, or an arylalkyl;    -   R¹³ is hydrogen, hydroxy, alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   Y′ and Y are each independently hydrogen; halogen; hydroxyl;        cyano, sulfhydryl; amino; alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   R⁷ is hydrogen, dialkylamino, thiourea, diazonium salt,        thiocarboxamide, or nitro;    -   R⁹ is hydrogen, thiourea, diazonium salt, thiocarboxamide, or        nitro; and pharmaceutically acceptable salts thereof, provided        that R⁹ is not hydrogen when R⁷ is hydrogen or dialkylamino.

DETAILED DESCRIPTION OF THE INVENTION

The present invention pertains, at least in part, to novel 7- and9-substituted tetracycline urea, thiourea, carbamate, thiocarbamate,amino-thiazolyl, and amino-heteroaryl compounds. These compounds can beused to treat numerous tetracycline compound-responsive states, such asbacterial infections and neoplasms, as well as other known applicationsfor tetracycline compounds, such as tetracycline efflux blockers andgene expression modulation.

In one embodiment, the invention includes 7- and 9-substitutedtetracycline compounds. Preferably, the substituted tetracyclinecompounds are of formula (I):

wherein:

-   -   X is CHC(R¹³Y′Y), CR^(6′)R⁶, S, NR⁶, or O;    -   R² is hydrogen, alkyl, alkynyl, alkoxy, alkylthio,        alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic or a prodrug moiety;    -   R⁴ and R^(4′) are each hydrogen, alkyl, alkenyl, alkynyl,        alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,        arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrug        moiety;    -   R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug        moiety;    -   R⁵ is hydrogen, hydroxyl, or a prodrug moiety;    -   R⁶, R^(6′), and R⁸ are each independently hydrogen, alkyl,        alkenyl, alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl,        alkylsulfonyl, alkylamino, arylalkyl, or halogen;    -   R⁷ is hydrogen, dialkylamino, heteroaryl-amino, or        NR^(7c)C(═W′)WR^(7a);    -   R¹³ is hydrogen, hydroxy, alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   Y′ and Y are each independently hydrogen, halogen, hydroxyl,        cyano, sulfhydryl, amino, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or        arylalkyl;    -   R⁹ is hydrogen, heteroaryl-amino, or NR^(9c)C(═Z′)ZR^(9a);    -   Z is CR^(9d)R^(9e), NR^(9b), or O;    -   Z′ is O or S;    -   R^(9a), R^(9b), R^(9c), R^(9d), and R^(9e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, alkylsulfonyl, arylsulfonyl,        alkoxycarbonyl, arylcarbonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic, absent, or a prodrug moiety, and        R^(9d) and R^(9e) may be linked to form a ring;    -   W is CR^(7d)R^(7e), NR^(7b) or O;    -   W′ is O or S; and    -   R^(7a), R^(7b), R^(7c), R^(7d), and R^(7e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, arylsulfonyl, alkoxycarbonyl,        arylcarbonyl, alkylamino, arylalkyl, aryl, heterocyclic,        heteroaromatic, absent, or a prodrug moiety, and R^(7d) and        R^(7e) may be linked to form a ring, and pharmaceutically        acceptable salts thereof, provided that R⁹ is not hydrogen when        R⁷ is dialkylamino or hydrogen.

The term “tetracycline compound” includes many compounds with a similarring structure to tetracycline. Examples of tetracycline compoundsinclude: tetracycline, chlortetracycline, oxytetracycline,demeclocycline, methacycline, sancycline, doxycycline, and minocycline.Other derivatives and analogues comprising a similar four ring structureare also included. Table 1 depicts tetracycline and several knowntetracycline derivatives. In an embodiment, the term “unsubstitutedtetracycline compounds,” includes tetracycline compounds wherein R⁷ isnot NR^(7c)C(═W′)WR^(7a) nor heteroaryl-amino and wherein R⁹ is notheteroaryl-amino nor NR^(9c)C(═Z′)ZR^(9a).

TABLE I

Tetracycline

Oxytetracycline

Demectocycline

Methacycline

Doxycycline

Chlorotetracycline

Minocycline

The term “substituted tetracycline compounds” includes tetracyclinecompounds with substitution at the 7- or 9-position. In one embodiment,the substitution at the 7- or 9-position enhances the ability of thesubstituted tetracycline compound to perform its intended function. Inan embodiment, the 9-substituted tetracycline compound is 9-substitutedminocycline (e.g., wherein R⁴ and R^(4′) are methyl, R⁵ is hydrogen, R⁷is dimethyl amino, and X is CR⁶R^(6′), wherein both R⁶ and R^(6′) arehydrogen atoms); 7- or 9-substituted doxycycline (e.g., wherein R⁴ andR^(4′) are methyl, R⁵ is hydroxyl, X is CR⁶R^(6′), R⁶ is methyl andR^(6′) is hydrogen); or a 7- or 9-substituted sancycline (wherein R⁴ andR^(4′) are methyl; R⁵ is hydrogen, X is CR⁶R^(6′), R⁶ and R^(6′) arehydrogen atoms). In a further embodiment, R⁵ may be a protected hydroxylgroup, e.g., a prodrug moiety. Examples of prodrug moieties include, forexample, acyl esters and propionoic acid esters. In certain embodiments,the prodrug moiety is aroyl, alkanoyl, or alkaroyl and may or may not becleaved in vivo to the hydroxyl group. In an embodiment, R^(2′), R³, R⁸,R¹⁰, R¹¹, and R¹² are each hydrogen. In certain embodiments of theinvention, the term substituted tetracycline compounds includestetracycline compounds wherein least one of R⁷ or R⁹ isheteroaryl-amino, NR^(7c)C(═W′)WR^(7a), or NR^(9c)C(═Z′)ZR^(9a).

The term “9-substituted tetracycline compounds” includes, in oneembodiment, compounds wherein R⁹ is amino-heteroaryl orNR^(9c)C(═Z′)ZR^(9a). In a further embodiment, R^(9c) is hydrogen. Inanother, Z′ is oxygen or sulfur. In an embodiment, Z is oxygen orNR^(9b), wherein R^(9b) is hydrogen. In another further embodiment,R^(9a) may be hydrophobic. R^(9a) may also be alkyl, alkenyl (e.g.,ethenyl, propenyl, butenyl, etc.), alkynyl, aryl (e.g., phenyl,heteroaryl, etc.), arylalkyl, or multicyclic (e.g., polycyclic, e.g.,steroidyl, e.g., chlolesteroidyl).

In one embodiment, R^(9a) is substituted or unsubstituted alkyl (e.g.,methyl, ethyl, t-butyl, n-butyl, i-butyl, or n-pentyl.) Examples ofpossible substituents include but are not limited to, alkyl, alkenyl,halogen, hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl,arylcarbonyloxy, alkoxycarbonylamino, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, aminoalkyl, arylalkylcarbonyl, alkenylcarbonyl,alkoxycarbonyl, silyl, aminocarbonyl, alkylthiocarbonyl, phosphate,aralkyl, phosphonato, phosphinato, cyano, amino, acylamino, amido,imino, sulfhydryl, alkylthio, sulfate, arylthio, thiocarboxylate,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro, cyano, azido,heterocyclyl, alkylaryl, aryl and heteroaryl. In certain embodiments,the substituents are alkoxycarbonyl, amino, arylcarbonyl, halogen,hydroxy, alkylamino, alkoxy, or aryl. In certain embodiments, thesubstituent is halogen (e.g., bromine, chlorine, iodine, fluorine).

In a further embodiment, R^(9a) includes at least one aryl group, e.g.,heteroaryl, phenyl, naphthyl, fluorene, etc. Fluorene is a moiety of theformula:

In one embodiment, R^(9a) is aryl, e.g., substituted or unsubstitutedphenyl. Examples of substituents include, but are not limited to, alkyl(e.g., unsubstituted, e.g., methyl, ethyl, propyl, butyl, orsubstituted, e.g., chloromethyl, dichloromethyl, perchloromethyl,fluoromethyl, difluoromethyl, perfluoromethyl, etc.), alkenyl, alkynyl,aryl, alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), aryloxy,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, amido,halogen, nitro, azo, alkyl sulfonyl, and arylsulfonyl.

In another embodiment, R⁹ is amino-heteroaryl (e.g., —NH-heteroaryl,e.g., amino-thioazolyl). The thioazolyl substituent may be substitutedwith substituents such as phenyl rings. Scheme 3 below shows somerepresentative substituents of the thioazole ring. For example, in oneembodiment, the thiazole can be substituted with a phenyl group, abiphenyl group, an adamantyl group, etc. The substituents of thethiazole can also be further substituted, e.g., with an electrondonating group, or an electron withdrawing group. Examples of electronwithdrawing substituents include aryl groups (e.g., phenyl), halogens(e.g., chlorine, bromine, or fluorine), alkoxy groups (e.g., methoxy,ethoxy), amines (e.g., secondary amines, such as, diethylamine,dimethylamine unsubstituted amines, etc.), nitro groups, etc. In otherembodiments, the thiazolyl ring is linked to the tetracycline compoundthrough an ether (—O—), alkyl, or other linkage which allows thesubstituted tetracycline compound to perform its intended function.

For example, in one embodiment, R⁹ is substituted or unsubstitutedheteroaryl-amino, e.g., thiazolyl amino. Examples of substituents of theheteroaryl include, but are not limited to, alkyl, alkenyl, halogen,hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl, arylcarbonyloxy,alkoxycarbonylamino, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, alkylaminoacarbonyl, arylalkyl aminocarbonyl,alkenylaminocarbonyl, alkylcarbonyl, arylcarbonyl, aminoalkyl,arylalkylcarbonyl, alkenylcarbonyl, alkoxycarbonyl, silyl,aminocarbonyl, alkylthiocarbonyl, phosphate, aralkyl, phosphonato,phosphinato, cyano, amino, acylamino, amido, imino, sulfhydryl,alkylthio, sulfate, arylthio, thiocarboxylate, alkylsulfinyl, sulfonato,sulfamoyl, sulfonamido, nitro, cyano, azido, heterocyclyl, alkylaryl,aryl and heteroaryl.

In certain embodiments, the substituents of the thiazolyl include alkyl(e.g., methyl, ethyl, propyl, butyl, etc.), halogen (e.g., fluorine,bromine, chlorine, iodine, etc.), alkoxy (e.g., methoxy, propoxy,ethoxy, etc.), aryl (e.g., substituted or unsubstituted phenyl orheteroaryl).

In an embodiment, the aryl thiazolyl substituent is substituted with oneor more substituents. Examples of substituents include, but are notlimited to, alkyl (e.g., methyl, ethyl, propyl, butyl, etc.), alkenyl,alkynyl, aryl, alkoxy, aryloxy, alkylcarbonyl, arylcarbonyl, amido,trifluoromethyl, halogen, nitro, azo, alkyl sulfonyl, alkoxycarbonyl(e.g., methoxycarbonyl, ethoxycarbonyl, etc.), aryloxycarbonyl, andarylsulfonyl.

The term “7-substituted tetracycline compounds” includes tetracyclinecompounds with substitution at the 7 position. Examples of tetracyclinecompounds which advantageously may be substituted at the 7 positioninclude tetracycline, sancycline, doxycycline, oxytetracycline,demeclocycline, or methacycline. In an advantageous embodiment, R⁷ isNR^(7c)C(═W′)WR^(7a), wherein R^(7c) may be hydrogen, W′ may be oxygenor sulfur. R^(7a) may be hydrophobic. R^(7a) may also be alkyl, alkenyl(e.g., ethenyl, propenyl, butenyl, etc.), alkynyl, aryl (e.g., phenyl,heteroaryl, etc.), arylalkyl, heteroaromatic, or multicyclic (e.g.,polycyclic, e.g., steroidyl, e.g., chlolesteroidyl). R^(7a) may alsoinclude at least one phenyl group, e.g., naphthyl or fluorene. In apreferred embodiment, W is oxygen or NR^(7b), wherein R^(7b) ishydrogen.

In one embodiment, R^(7a) is substituted or unsubstituted alkyl (e.g.,methyl, ethyl, t-butyl, n-butyl, i-butyl, or n-pentyl.) Examples ofpossible substituents include but are not limited to, alkyl, alkenyl,halogen, hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl,arylcarbonyloxy, alkoxycarbonylamino, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, aminoalkyl, arylalkylcarbonyl, alkenylcarbonyl,alkoxycarbonyl, silyl, aminocarbonyl, alkylthiocarbonyl, phosphate,aralkyl, phosphonato, phosphinato, cyano, amino, acylamino, amido,imino, sulfhydryl, alkylthio, sulfate, arylthio, thiocarboxylate,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro, cyano, azido,heterocyclyl, alkylaryl, aryl and heteroaryl. In certain embodiments,the substituents are alkoxycarbonyl, amino, arylcarbonyl, halogen,hydroxy, alkylamino, alkoxy, or aryl. In certain embodiments, thesubstituent is halogen (e.g., bromine, chlorine, iodine, fluorine). In afurther embodiment, R^(7a) includes at least one aryl group, e.g.,heteroaryl, phenyl, naphthyl, fluorene, etc.

In one embodiment, R^(7a) is aryl, e.g., substituted or unsubstitutedphenyl. Examples of substituents include, but are not limited to, alkyl(e.g., unsubstituted, e.g., methyl, ethyl, propyl, butyl, orsubstituted, e.g., chloromethyl, dichloromethyl, perchloromethyl,fluoromethyl, difluoromethyl, perfluoromethyl, etc.), alkenyl, alkynyl,aryl, alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), aryloxy,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, amido,halogen, nitro, azo, alkyl sulfonyl, and arylsulfonyl.

In another embodiment, R⁷ is amino-heteroaryl (e.g., —NH-heteroaryl,e.g., amino-thioazolyl). The thioazolyl substituent may be substitutedwith substituents such as phenyl rings. Scheme 3 below shows somerepresentative substituents of the thioazole ring. For example, in oneembodiment, the thiazole can be substituted with a phenyl group, abiphenyl group, an adamantyl group, etc. The substituents of thethiazole can also be further substituted, e.g., with an electrondonating group, or an electron withdrawing group. Examples of electronwithdrawing substituents include aryl groups (e.g., phenyl), halogens(e.g., chlorine, bromine, or fluorine), alkoxy groups (e.g., methoxy,ethoxy), amines (e.g., secondary amines, such as, diethylamine,dimethylamine unsubstituted amines, etc.), nitro groups, etc. In otherembodiments, the thiazolyl ring is linked to the tetracycline compoundthrough an ether (—O—), alkyl, or other linkage which allows thesubstituted tetracycline compound to perform its intended function.

For example, in one embodiment, R⁷ is substituted or unsubstitutedheteroaryl-amino, e.g., thiazolyl amino. Examples of substituents of theheteroaryl include, but are not limited to, alkyl, alkenyl, halogen,hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl, arylcarbonyloxy,alkoxycarbonylamino, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, alkylaminoacarbonyl, arylalkyl aminocarbonyl,alkenylaminocarbonyl, alkylcarbonyl, arylcarbonyl, aminoalkyl,arylalkylcarbonyl, alkenylcarbonyl, alkoxycarbonyl, silyl,aminocarbonyl, alkylthiocarbonyl, phosphate, aralkyl, phosphonato,phosphinato, cyano, amino, acylamino, amido, imino, sulfhydryl,alkylthio, sulfate, arylthio, thiocarboxylate, alkylsulfinyl, sulfonato,sulfamoyl, sulfonamido, nitro, cyano, azido, heterocyclyl, alkylaryl,aryl and heteroaryl.

In certain embodiments, the substituents of the thiazolyl include alkyl(e.g., methyl, ethyl, propyl, butyl, etc.), halogen (e.g., fluorine,bromine, chlorine, iodine, etc.), alkoxy (e.g., methoxy, propoxy,ethoxy, etc.), aryl (e.g., substituted or unsubstituted phenyl orheteroaryl).

In an embodiment, the aryl thiazolyl substituent is substituted with oneor more substituents. Examples of substituents include, but are notlimited to, alkyl (e.g., methyl, ethyl, propyl, butyl, etc.), alkenyl,alkynyl, aryl, alkoxy, aryloxy, alkylcarbonyl, arylcarbonyl, amido,trifluoromethyl, halogen, nitro, azo, alkyl sulfonyl, alkoxycarbonyl(e.g., methoxycarbonyl, ethoxycarbonyl, etc.), aryloxycarbonyl, andarylsulfonyl.

In a further embodiment of the invention, R^(2′), R³, R¹⁰, R¹¹, and R¹²of the substituted tetracycline compounds are each hydrogen atoms. Inanother further embodiment, R⁴ and R^(4′) are each alkyl, e.g., loweralkyl, and, advantageously, methyl. In another embodiment, X isCR⁶R^(6′). R⁶ and R^(6′) are selected from the group consisting ofhydrogen, methyl, and hydroxy groups.

In another embodiment, the invention also pertains to compounds whereinboth R⁹ and R⁷ are not hydrogen. These compounds may be referred to as7- and 9-disubstituted compounds. The invention pertains to compoundswith any combination of 7- and 9-substituents disclosed herein.

Examples of compounds of the invention include those disclosed in Table2, in addition to the compounds listed below. The invention alsopertains to pharmaceutically acceptable salts of any of these compoundsas well as enantiomers, and mixtures of the compounds. Examples ofcompounds of the invention include, but are not limited to:

-   Doxycycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline urea;-   9-(3-Methyl-1-butyl) doxycycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl doxycycline urea;-   FMOC 9-amino doxycycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline urea;-   9-(4′-Fluorophenyl) doxycycline carbamate;-   9-(4′-Methoxyphenyl) doxycycline carbamate;-   9-BOC amino doxycycline;-   9-(Phenylthiazolyl) amino doxycycline;-   9-(Ethylthiazolyl) amino doxycycline;-   (4-Fluorophenylthiazolyl) amino doxycycline;-   9-(4′-Methoxyphenylthiazolyl) amino doxycycline;-   9-(3′-Nitrophenylthiazolyl) amino doxycycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl minocycline carbamate;-   9-(Phenylthiazolyl) amino sancycline;-   9-(Adamantylthiazolyl) amino doxycycline;-   9-(Naphthyn-1-yl urea) Doxycycline 5-propanoic acid ester;-   Doxycycline 9-Thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline thiourea;-   9-(3-methyl-1-butyl) doxycycline thiourea;-   9-Phenyl doxycycline thiourea;-   9-t-Butyl doxycycline thiourea;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   9-(4′-Fluorophenyl) doxycycline thiocarbamate;-   9-(4-Methoxyphenyl) doxycycline thiocarbamate;-   9-Neopentyl minocycline thiocarbamate;-   9-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester;-   Minocycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline urea;-   9-(3-Methyl-1-butyl) minocycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl minocycline urea;-   FMOC 9-amino minocycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) minocycline urea;-   9-(4′-Fluorophenyl) minocycline carbamate;-   9-(4′-Methoxyphenyl) minocycline carbamate;-   9-BOC amino minocycline;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Ethylthiazolyl) amino minocycline;-   (4′-Fluorophenylthiazolyl) amino minocycline;-   9-(4′-Methoxyphenylthiazolyl) amino minocycline;-   9-9-(3′-Nitrophenylthiazolyl) amino minocycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl doxycycline carbamate;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Adamantylthiazolyl) amino minocycline;-   Minocycline 9-thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline thiourea;-   9-(3′-Methyl-1-butyl) minocycline thiourea;-   9-Phenyl minocycline thiourea;-   9-t-Butyl minocycline thiourea;-   9-(4′-Fluorophenyl) minocycline thiocarbamate;-   9-(4′-Methoxyphenyl) minocycline thiocarbamate;-   9-Neopentyl doxycycline thiocarbamate;-   9-(2′-Bromoethyl) doxycycline carbamate;-   9-(n-Pentyl) minocycline carbamate;-   9-(4′-Benzoylbenzoyl) amino doxycycline;-   7-(3′-Nitrophenylthiazolyl) amino sancycline;-   9-(3′-Ethoxycarbonylthiazolyl) amino doxycycline;-   7-(4′-Methylphenyl) sancycline carbamate;-   9-(4′-Trifluoromethoxyphenyl) minocycline urea;-   9-(3′,5′-diperfluorophenyl) minocycline thiourea;-   9-Prop-2′-enyl minocycline carbamate;-   9-(4′-Chloro, 2′-nitrophenyl) minocycline urea;-   9-Ethyl minocycline carbamate;-   9-n-Butyl minocycline carbamate;-   9-n-But-3-enyl minocycline carbamate;-   Doxycycline 7-carbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline urea;-   7-(3-Methyl-1-butyl) doxycycline urea;-   7-Phenyl doxycycline urea;-   7-t-Butyl doxycycline urea;-   7-Fmoc amino doxycycline;-   7-(4′-Chloro-2-trifluoromethylphenyl) doxycycline urea;-   7-(4′-Fluorophenyl) doxycycline carbamate;-   7-(4′-Methoxyphenyl) doxycycline carbamate;-   7-BOC amino doxycycline;-   7-(3′Phenylthiazolyl) amino doxycycline;-   7-(3′-Ethylthiazolyl) amino doxycycline;-   7-(4″-Fluorophenylthiazolyl) amino doxycycline;-   7-(4″-Methoxyphenylthiazolyl) amino doxycycline;-   7-(Phenylthiazolylamino)-sancycline;-   7-(3′-Nitrophenylthiazolyl) amino doxycycline;-   7-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   7-(Adamantylthiazolyl) amino doxycycline;-   Doxycycline 7-thiocarbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline thiourea;-   7-(3-Methyl-1-butyl) doxycycline thiourea;-   7-Phenyl amino doxycycline thiourea;-   7-t-butyl amino doxycycline thiourea;-   7-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   7-(4′-Fluorophenyl) doxycycline thiocarbamate;-   7-(4′-Methoxyphenyl) doxycycline thiocarbamate;-   7-(Naphthyn-1-yl) doxycycline urea 5-propanoic acid ester;-   9-i-Butyl minocycline carbamate,-   7-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester, and    pharmaceutically acceptable salts thereof.

Other compounds of the invention include compounds having the followingstructures:

The invention includes methods for synthesizing 7- and/or 9-substitutedtetracycline compounds using reactive intermediates, such as thioureas,thiocarboxyamides, and diazonium salts, advantageously, at the R⁷ and/orR⁹ position of tetracycline compound of formula (I). In one embodiment,the invention pertains to methods of synthesizing 9- and/or7-substituted tetracycline compounds by contacting a reactiveintermediate with appropriate reagents under appropriate conditions,such that a 7- and/or 9-substituted tetracycline compound is formed.Examples of appropriate reagents and conditions are described in schemes1-3 and in example 1.

The term “reactive intermediates” includes species which are generatedduring the synthesis of the 7- and/or 9-substituted tetracyclinecompounds of Formula (I). These intermediates may or may not be stableunder reaction conditions and may or may not be isolatable. However, oneof skill in the art can appreciate that these reactive intermediates canbe used to generate other 7- and/or 9-substituted tetracyclinecompounds. The term “reactive intermediates” includes all intermediateswhich are synthesized or can be synthesized using the methodologydiscussed herein. Examples of reactive intermediates of the inventioninclude 7- and/or 9-diazonium salts, 7- and/or 9-thiocarboxyamates, 7-and/or 9-anilino compounds, 7- and/or 9-amino tetracycline compounds, 7-and/or 9-nitro tetracycline compounds, 7- and/or 9-urea derivatives, 7-and/or 9-carbamate derivatives, etc.

The language “appropriate conditions” include conditions known in theart and conditions described herein to convert the reactive intermediateto a 7- and/or 9-substituted tetracycline compound of formula (I) oranother desired tetracycline compound.

The language “appropriate reagents” include reagents known in the artand reagents described herein to convert the reactive intermediate to atetracycline compound of formula (I) or another desired tetracyclinecompound.

In another embodiment, the invention includes methods of synthesizing 7-and/or 9-substituted tetracycline compounds outlined in the followingschemes. Although in each scheme the reaction is shown for only one ortwo tetracycline compounds, one of skill in the art will appreciate thatsimilar reactions can be also be performed with other tetracyclinecompounds.

In an embodiment, the invention pertains to a method for synthesizing 7-and/or 9-substituted tetracycline compounds by contacting anunsubstituted tetracycline compound with a nitrating agent, to form a 7-and/or 9-nitro substituted tetracycline compound. The 7- and/or 9-nitrosubstituted tetracycline compound is then hydrogenated with ahydrogenating agent to form a 7- and/or 9-amino substituted tetracyclinecompound. The 7- and/or 9-amino substituted tetracycline compound iscontacted with an amino reactive compound, thereby forming a 7- and/or9-substituted tetracycline compound.

The term “nitrating agent” includes compounds and chemicals which, underappropriate conditions, can introduce a nitro group (—NO₂) to atetracycline compound. Advantageous nitrating agents include, forexample, NaNO₂. Other methods of nitration are known in the art and arealso included (see, for example, March, Advanced Organic Chemistry, JohnWiley & Sons: New York, 1992, p. 522-525, and references cited therein).Advantageously, when the nitrating agent is NaNO₂, the reaction isconducted under acidic conditions.

The term “hydrogenating agent” includes compounds and chemicals which,under appropriate conditions, can convert a nitro group to an aminogroup (—NH₂). Examples of preferred hydrogenating agents include H₂ gaswith a transition metal catalyst, advantageously, platinum. Othermethods of converting nitro groups to amino groups are known in the art(see, for example March, Advanced Organic Chemistry, John Wiley & Sons:New York, 1992, p. 1216-1217, and references cited therein).

The term “amino reactive compound” includes compounds and moleculeswhich can be reacted with the 7- and/or 9-amino tetracycline derivativeto form a desired 7- and/or 9-substituted tetracycline compound, or aprecursor thereof. Examples of advantageous amino reactive compounds forthe formation of 9-substituted urea and carbamate tetracycline compoundsinclude substituted and unsubstituted isocyanates and chloroformates.Scheme 1 below depicts the synthesis for a 9-substituted doxycyclinecompounds, but the methodology can be applied both to other tetracyclinecompounds and 7-substituted tetracycline compound. The depicted methodincludes treating an unsubstituted tetracycline compound (1-1) with acid(e.g., H₂SO₄) and a nitrating agent (e.g., sodium or potassium nitrate)to form the reactive nitro substituted tetracycline intermediate (1-2).The reactive nitro substituted tetracycline intermediate can be reducedto the corresponding amine (1-3) by hydrogenating reagents known in theart (e.g., hydrogen with metal catalysts, platinum oxide or the like) toproduce the amino substituted tetracycline compound (1-3). The aminosubstituted tetracycline compound (1-3) can then be reacted in mild basewith substituted isocyanates (1-4) to form mixed urea substitutedtetracycline compounds (1-5). The amino substituted tetracyclinecompounds (1-3) can also be reacted with substituted or unsubstitutedchloroformates (1-6) to form substituted carbamates tetracyclinecompounds (1-7). Additionally, the amino substituted tetracyclinecompounds (1-3) can be reacted with other species, such as thethioisocyanates (1-8), to form other desirable derivatives, such as thethioureas (1-9).

The initial nitration of the tetracycline compound may produce a mixtureof the 7- and 9-substituted isomers. An ordinarily skilled artisan willbe able to appreciate that the isomers can be separated by conventionalmethods after any of the reactions mentioned above. Techniques forseparating isomers are well known in the art. For example, the aminosubstituted tetracycline compounds (e.g., 1-3) can be separated fromother positional isomers by techniques known in the art, e.g.,preparative HPLC on C18-reverse phase silica gel with a binary gradientsystem. The amino tetracycline compounds can also be prepared accordingto U.S. Pat. No. 3,483,251 through a reductive alkylation of7-(N,N″-dicarbobenzyloxyhydrazino)tetracyclines. Furthermore, other 7-and/or 9-substituted tetracycline compounds can be synthesized byreacting the amino intermediate with amino reactive substrate.

The reactive 7- and/or 9-amino substituted tetracycline compounds areincluded as reactive intermediates. The amino substituted tetracyclinecompounds can react with other chemical species such as isocyanatederivatives or isothiocyanate derivatives to produce 7- and/or9-position ureas and thioureas (thiocarbocarboxyamides) as shown inScheme 1. The 7- and/or 9-position urea and thiourea tetracyclinecompounds are reactive intermediates and can be used in the synthesis ofa wide variety of 7- and/or 9-substituted tetracycline compounds. Forexample, the 7- and/or 9-position thioureas can be used to formamino-heterocyclic moieties by reactions shown in Scheme 2, below.

For example, 9-amino substituted tetracycline compound (2-1) can bereacted with Fmoc-NCS to produce a 9-Fmoc thiourea substitutedtetracycline compound (2-2). The Fmoc substituted thiourea substitutedtetracycline compound (2-2) can be deprotected using methods known inthe art to form the 9-thiourea substituted tetracycline compound (2-3).The 9-thiourea substituted tetracycline compound (2-3) is a reactiveintermediate, which can be reacted with α-haloketones (2-4, e.g.,substituted or unsubstituted α-haloketones, etc.), to produce9-thiazolylamino substituted tetracycline compounds (2-5). Thismethodology can also be used to form 7-position thiourea substitutedtetracycline reactive intermediates as well as 7-position thiazolylaminotetracycline compounds.

Thiourea tetracycline reactive intermediates also can be used asreactive intermediates in the synthesis of, for example, spiro and fusedcyclopentapyrozole and pyrimidine derivatives (Albar et al., J. Chem.Res., Synop., (2), 40-41 (1997); pyridazinedione derivatives (SharafEl-Din, Alexandria J. Pharm. Sci., 11(1) 9-12 (1997)); benzothiazoleacrylic acid derivatives (Kassem, et al., Pak. J. Sci. Ind. Res. 38(11-12) 424-427 (1995)); thiazoline, aryazothioazole and pyrazolederivatives (Abdelhamid, A. Phosphorous, Sulfur, Silicon Related Elem.119 (181-191) (1996)); pyrimidine derivatives (Fikry, J. Indian Chem.Soc., 73(12), 698-699 (1996)); aminothiazole-arbonitrile derivatives(Shiono, JP 95-331456); benzimidazole derivatives (Omar et al. Egypt. J.Pharm. Sci. 37(1-6), 609-620 (1996)); benzylthiazolidine derivatives(Morita et al., JP 95-200268); clonidine derivatives (Pierce, et al. WO95/21818); pyrimidine derivatives (Nassar, et al. Egypt. J. Chem., 40(3)239-247 (1997)); bicyclic derivatives (Zhu, et al. Hanneng Cailiao 5(4),165-170 (1997)); combinatorial libraries (Nefzi, et al. WO 98/19693);triazinoindole derivatives (Tomchin, et al. Khim.-Farm. Zh., 31(3),19-27 (1997); Tomchin et al., Khim.-Farm. Zh., 32(3) 7-10 (1998)); arylthio derivatives (Chikalia, et al. Proc. Nat. Acad. Sci. India 68(A), I,1998); and α-amino acid derivatives (Beyer, et al. Tetrahedron, 52(17)6233-6240 (1996)).

As depicted in Scheme 3,5-esters of 7- and/or 9-substituted tetracyclinecompounds (3-1 and 3-3) can be formed by dissolving the 7- and/or9-substituted tetracycline compounds in strong acid and adding theappropriate carboxylic acid. Examples of strong acids include anhydroushydrogen fluoride, methanesulphonic acid, and trifluoromethanesulfonicacid.

The invention also pertains to a method for synthesizing a 7- or9-substituted tetracycline compound of formula (I), by contacting areactive intermediate with appropriate reagents under appropriateconditions, such that a substituted tetracycline compound is formed. Thecompound of formula (I) is:

wherein:

-   -   X is CHC(R¹³Y′Y), CR^(6′)R⁶, S, NR⁶, or O;    -   R² is hydrogen, alkyl, alkynyl, alkoxy, alkylthio,        alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic or a prodrug moiety;    -   R⁴ and R^(4′) are each hydrogen, alkyl, alkenyl, alkynyl,        alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,        arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrug        moiety;    -   R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug        moiety;    -   R⁵ is hydrogen, hydroxyl, or a prodrug moiety;    -   R⁶, R^(6′), and R⁸ are each independently hydrogen, alkyl,        alkenyl, alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl,        alkylsulfonyl, alkylamino, arylalkyl, or halogen;    -   R⁷ is hydrogen, dialkylamino, heteroaryl-amino, or        NR^(7c)C(═W′)WR^(7a);    -   R¹³ is hydrogen, hydroxy, alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   Y′ and Y are each independently hydrogen; halogen; hydroxyl;        cyano, sulfhydryl; amino; alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   R⁹ is hydrogen, NR^(9c)C(═Z′)ZR^(9a), or heteroaryl-amino;    -   Z is CR^(9d)R^(9e), NR^(9b), or O;    -   Z′ is O or S;    -   R^(9a), R^(9b), R^(9c), R^(9d), and R^(9e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, alkylsulfonyl, arylsulfonyl,        alkoxycarbonyl, arylcarbonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic, absent, or a prodrug moiety;    -   W is CR^(7d)R^(7e), NR^(7b) or O;    -   W′ is O or S; and    -   R^(7a), R^(7b), R^(7c), R^(7d), and R^(7e) are each        independently hydrogen, alkyl, alkenyl, alkynyl, alkoxy,        alkylthio, alkylsulfinyl, arylsulfonyl, alkoxycarbonyl,        arylcarbonyl, alkylamino, arylalkyl, aryl, heterocyclic,        heteroaromatic, absent, or a prodrug moiety;    -   and pharmaceutically acceptable salts thereof, provided that R⁹        is not hydrogen when R⁷ is dialkylamino or hydrogen.

In one embodiment, the reactive intermediate is a 7- and/or 9-diazoniumsalt, a 7- and/or 9-nitro compound, a 7- and/or 9-thiourea, or a 7-and/or 9-thiocarboxamide.

The invention also pertains to reactive intermediates of the formula:

wherein:

-   -   X is CHC(R¹³Y′Y), CHR⁶, S, NR⁶, or O;    -   R² is hydrogen, alkyl, alkynyl, alkoxy, alkylthio,        alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl,        heterocyclic, heteroaromatic or a prodrug moiety;    -   R⁴ and R^(4′) are each hydrogen, alkyl, alkenyl, alkynyl,        alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,        arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrug        moiety;    -   R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug        moiety;    -   R⁵ is hydrogen, hydroxyl, or a prodrug moiety;    -   R⁶ and R⁸ are each independently hydrogen, alkyl, alkenyl,        alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,        alkylamino, or an arylalkyl;    -   R¹³ is hydrogen, hydroxy, alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   Y′ and Y are each independently hydrogen; halogen; hydroxyl;        cyano, sulfhydryl; amino; alkyl; alkenyl; alkynyl; alkoxy;        alkylthio; alkylsulfinyl; alkylsulfonyl; alkylamino; or an        arylalkyl;    -   R⁹ is hydrogen, thiourea, diazonium salt, thiocarboxamide, or        nitro;    -   R⁷ is hydrogen, thiourea, dialkylamino, diazonium salt,        thiocarboxamide, or nitro; and pharmaceutically acceptable salts        thereof, provided that R⁹ is not hydrogen when R⁷ hydrogen or        dialkylamino.

In a further embodiment, R⁷ is hydrogen or dialkylamino, when R⁹ isthiourea, diazonium salt, thiocarboxamide, or a nitro moiety. Inanother, R⁹ is hydrogen when R⁷ is thiourea, diazonium salt,thiocarboxamide, or a nitro moiety.

Unless specifically indicated, the chemical groups of the presentinvention may be substituted or unsubstituted. Further, unlessspecifically indicated, the chemical substituents may in turn besubstituted or unsubstituted. In addition, multiple substituents may bepresent on a chemical group or substituent. Examples of substituentsinclude alkyl, alkenyl, alkynyl, halogen, hydroxyl, alkylcarbonyloxy,arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxyl,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,formyl, trimethylsilyl, phosphate, phosphonato, phosphinato, cyano,amino (including alkyl amino, dialkylamino, arylamino, diarylamino, andalkylarylamino), acylamino (including alkylcarbonylamino,arylcarbonylamino, carbamoyl and ureido), amido, imino, sulfhydryl,alkylthio, arylthio, thiocarboxylate, sulfates, alkylsulfinyl,sulfonato, sulfamoyl, sulfonamido, nitro, trifluoromethyl, cyano, azido,heterocyclyl, alkylaryl, aromatic or heteroaromatic moieties,cholesterol, arylsulfonyl, azo, thiazolyl, adamantyl, and phosphonyl.

The term “alkyl” includes saturated aliphatic groups, includingstraight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl(alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkylsubstituted alkyl groups. The term alkyl further includes alkyl groups,which can further include oxygen, nitrogen, sulfur or phosphorous atomsreplacing one or more carbons of the hydrocarbon backbone, e.g., oxygen,nitrogen, sulfur or phosphorous atoms. In an embodiment, a straightchain or branched chain alkyl has 10 or fewer carbon atoms in itsbackbone (e.g., C₁-C₁₀ for straight chain, C₃-C₁₀ for branched chain),and in another embodiment, 4 or fewer. Likewise, in certain embodiments,cycloalkyls have from 4-7 carbon atoms in their ring structure, and mayhave 5 or 6 carbons in the ring structure.

Moreover, the term alkyl includes both “unsubstituted alkyls” and“substituted alkyls”, the latter of which refers to alkyl moietieshaving substituents replacing a hydrogen on one or more carbons of thehydrocarbon backbone. Such substituents can include, for example,halogen, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkoxycarbonyl,aminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate, phosphonato,phosphinato, cyano, amino (including alkyl amino, dialkylamino,arylamino, diarylamino, and alkylarylamino), acylamino (includingalkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), amidino,imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfates,sulfonato, sulfamoyl, sulfonamido, nitro, trifluoromethyl, cyano, azido,heterocyclyl, alkylaryl, or an aromatic or heteroaromatic moiety.Cycloalkyls can be further substituted, e.g., with the substituentsdescribed above. An “alkylaryl” moiety is an alkyl substituted with anaryl (e.g., phenylmethyl (benzyl)).

The term “aryl” includes aryl groups, including 5- and 6-memberedsingle-ring aromatic groups that may include from zero to fourheteroatoms, for example, benzene, pyrrole, furan, thiophene, imidazole,benzoxazole, benzothiazole, triazole, tetrazole, pyrazole, pyridine,pyrazine, pyridazine and pyrimidine, and the like. Aryl groups alsoinclude polycyclic fused aromatic groups such as naphthyl, quinolyl,indolyl, and the like. Those aryl groups having heteroatoms in the ringstructure may also be referred to as “aryl heterocycles”, “heteroaryls”or “heteroaromatics”. The aromatic ring can be substituted at one ormore ring positions with such substituents as described above, as forexample, halogen, hydroxyl, alkoxy, alkylcarbonyloxy, arylcarbonyloxy,alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl,alkoxycarbonyl, aminocarbonyl, alkylthiocarbonyl, phosphate,phosphonato, phosphinato, cyano, amino (including alkyl amino,dialkylamino, arylamino, diarylamino, and alkylarylamino), acylamino(including alkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido),amidino, imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate,sulfates, sulfonato, sulfamoyl, sulfonamido, nitro, trifluoromethyl,cyano, azido, heterocyclyl, alkylaryl, or an aromatic or heteroaromaticmoiety. Aryl groups can also be fused or bridged with alicyclic orheterocyclic rings which are not aromatic so as to form a polycycle(e.g., tetralin).

The terms “alkenyl” and “alkynyl” include unsaturated aliphatic groupsanalogous in length and possible substitution to the alkyls describedabove, but that contain at least one double or triple bond,respectively.

Unless the number of carbons is otherwise specified, “lower alkyl” asused herein means an alkyl group, as defined above, but having from oneto five carbon atoms in its backbone structure. Likewise, “loweralkenyl” and “lower alkynyl” have similar chain lengths.

The terms “alkoxyalkyl”, “polyaminoalkyl” and “thioalkoxyalkyl” includealkyl groups, as described above, which further include oxygen, nitrogenor sulfur atoms replacing one or more carbons of the hydrocarbonbackbone, e.g., oxygen, nitrogen or sulfur atoms.

The terms “polycyclyl,” “multicycle” or “polycyclic radical” refer totwo or more cyclic rings (e.g., cycloalkyls, cycloalkenyls,cycloalkynyls, aryls and/or heterocyclyls) in which two or more carbonsare common to two adjoining rings, e.g., the rings are “fused rings”.Rings that are joined through non-adjacent atoms are termed “bridged”rings. Each of the rings of the polycycle can be substituted with suchsubstituents as described above, as for example, halogen, hydroxyl,alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkoxycarbonyl,aminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate, phosphonato,phosphinato, cyano, amino (including alkyl amino, dialkylamino,arylamino, diarylamino, and alkylarylamino), acylamino (includingalkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), amidino,imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfates,sulfonato, sulfamoyl, sulfonamido, nitro, trifluoromethyl, cyano, azido,heterocyclyl alkyl, alkylaryl, or an aromatic or heteroaromatic moiety.Examples of “multicyclic” moieties include steroids, such as, forexample, cholesterol.

The term “heteroatom” as used herein means an atom of any element otherthan carbon or hydrogen. Preferred heteroatoms are nitrogen, oxygen,sulfur and phosphorus.

Suitable alkanoyl groups include groups having 1 to about 4 or 5carbonyl groups. Suitable aroyl groups include groups having one or morecarbonyl groups as a substituent to an aryl group such as phenyl orother carbocyclic aryl. Suitable alkaroyl groups have one or morealkylcarbonyl groups as a substituent to an aryl group such asphenylacetyl and the like. Suitable carbocyclic aryl groups have 6 ormore carbons such as phenyl, naphthyl and the like. Suitable aryloylgroups are carbocyclic aryl groups that are substituted with one or morecarbonyl groups, typically 1 or 2 carbonyl groups.

Prodrugs are compounds which are converted in vivo to active forms (see,e.g., R. B. Silverman, 1992, “The Organic Chemistry of Drug Design andDrug Action”, Academic Press, Chp. 8). Prodrugs can be used to alter thebiodistribution (e.g., to allow compounds which would not typicallyenter the reactive site of the protease) or the pharmacokinetics for aparticular compound. For example, a hydroxyl group, can be esterified,e.g., with a carboxylic acid group to yield an ester. When the ester isadministered to a subject, the ester is cleaved, enzymatically ornon-enzymatically, reductively or hydrolytically, to reveal the hydroxylgroup.

The language “prodrug moiety” includes moieties which can be metabolizedin vivo to yield an active compound. For example, the term includesmoieties which can modify certain functional groups of the substitutedtetracycline compounds, such as, but not limited to, hydroxyl groups andamino groups. In an embodiment, the prodrugs moieties are metabolized invivo by esterases or by other mechanisms to hydroxyl groups, amino,amido or other groups which allow the substituted tetracycline compoundto perform its intended function. Examples of prodrugs and their usesare well known in the art (See, e.g., Berge et al. (1977)“Pharmaceutical Salts”, J. Pharm. Sci. 66:1-19). Some prodrugs can beprepared in situ during the final isolation and purification of thecompounds, or by separately reacting the purified compound in its freeacid form or hydroxyl with a suitable esterifying agent. Hydroxylgroups, for example, can be converted into esters via treatment with acarboxylic acid (see, for example, Scheme 3). Examples of prodrugmoieties include substituted and unsubstituted, branch or unbranchedlower alkyl ester moieties, (e.g., propionoic acid esters), loweralkenyl esters, di-lower alkyl-amino lower-alkyl esters (e.g.,dimethylaminoethyl ester), acylamino lower alkyl esters (e.g.,acetyloxymethyl ester), acyloxy lower alkyl esters (e.g.,pivaloyloxymethyl ester), aryl esters (phenyl ester), aryl-lower alkylesters (e.g., benzyl ester), substituted (e.g., with methyl, halo, ormethoxy substituents) aryl and aryl-lower alkyl esters, amides,lower-alkyl amides, di-lower alkyl amides, and hydroxy amides. Preferredprodrug moieties for hydroxyl groups are propionoic acid esters and acylesters. Amino or amido groups can be modified by methods known in theart to form Schiff bases and other prodrugs which may or may not bemetabolized in vivo.

It will be noted that the structure of some of the compounds of thisinvention includes asymmetric carbon atoms. It is to be understoodaccordingly that the isomers arising from such asymmetry (e.g., allenantiomers and diastereomers) are included within the scope of thisinvention, unless indicated otherwise. Such isomers can be obtained insubstantially pure form by classical separation techniques and bystereochemically controlled synthesis.

The invention also features a method for treating a tetracyclinecompound responsive state in a subject, by administering to the subjecta substituted tetracycline compound of the invention. Preferably, aneffective amount of the substituted tetracycline compound isadministered. In an embodiment, the substituted tetracycline compound isof formula (I). The invention includes methods of treating atetracycline compound responsive state using any one of the compoundsdescribed above or found in Table 2, below.

The term “subject” includes any animal or plant which is capable ofbeing treated or may obtain some benefit from the administration of asubstituted tetracycline compound of the invention. The term alsoinclude animals (e.g., birds, reptiles, fish, mammals, (e.g., cows,pigs, sheep, horses, cows, dogs, cats, squirrels, bears, monkeys,chimpanzees, gorillas, goats, ferrets, and, preferably, humans). Thesubject may be currently suffering from the tetracycline compoundresponsive state or may be at risk of suffering from the tetracyclinecompound responsive state. In an embodiment, the subject may beimmunocomprimised, e.g., suffering from AIDS, undergoing or recoveringfrom chemotherapy, or have an immune disorder.

The language “tetracycline compound responsive state” includes statewhich can be treated, prevented, or otherwise ameliorated by theadministration of a substituted tetracycline compound of the invention.Tetracycline compound responsive states include bacterial infections(including those which are resistant to other tetracycline compounds),cancer, diabetes, and other states for which tetracycline compounds havebeen found to be active (see, for example, U.S. Pat. Nos. 5,789,395;5,834,450; and 5,532,227). Compounds of the invention can be used toprevent or control important mammalian and veterinary diseases such asdiarrhea, urinary tract infections, infections of skin and skinstructure, ear, nose and throat infections, wound infection, mastitisand the like. In addition, methods for treating neoplasms usingtetracycline compounds of the invention are also included (van derBozert et al., Cancer Res., 48:6686-6690 (1988)).

Bacterial infections may be caused by a wide variety of gram positiveand gram negative bacteria. The compounds of the invention are useful asantibiotics against organisms which are resistant to other tetracyclinecompounds. The antibiotic activity of the tetracycline compounds of theinvention may be determined using the method discussed in Example 2, orby using the in vitro standard broth dilution method described in Waitz,J. A., National Commission for Clinical Laboratory Standards, DocumentM7-A2, vol. 10, no. 8, pp. 13-20, 2^(nd) edition, Villanova, Pa. (1990).

The tetracycline compounds may also be used to treat infectionstraditionally treated with tetracycline compounds such as, for example,rickettsiae; a number of gram-positive and gram-negative bacteria; andthe agents responsible for lymphogranuloma venereum, inclusionconjunctivitis, psittacosis. The substituted tetracycline compounds maybe used to treat infections of pneumococci, Salmonella, E. coli, S.aureus, E. hirae or E. faecalis. In one embodiment, the substitutedtetracycline compound is used to treat a bacterial infection that isresistant to other unsubstituted tetracycline antibiotic compounds(e.g., tetracycline compounds such as doxycycline, minocycline,sancycline, or tetracycline). In another embodiment, the substitutedtetracycline compounds of the invention are less cytotoxic to thesubject as compared to unsubstituted tetracycline compounds, such thatthe substituted tetracycline compounds may be given at a higher dosagewith out being fatal or excessively toxic to the subject. Thesubstituted tetracycline compound of the invention may be administeredwith a pharmaceutically acceptable carrier.

Examples of compounds of the invention which may advantageously be usedin the methods of the invention include substituted tetracyclinecompounds of formula (I), as well as compounds described in Table 2.Examples of compounds of the invention include:

-   Doxycycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline urea;-   9-(3-Methyl-1-butyl) doxycycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl doxycycline urea;-   FMOC 9-amino doxycycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline urea;-   9-(4′-Fluorophenyl) doxycycline carbamate;-   9-(4′-Methoxyphenyl) doxycycline carbamate;-   9-BOC amino doxycycline;-   9-(Phenylthiazolyl) amino doxycycline;-   9-(Ethylthiazolyl) amino doxycycline;-   (4-Fluorophenylthiazolyl) amino doxycycline;-   9-(4′-Methoxyphenylthiazolyl) amino doxycycline;-   9-(3′-Nitrophenylthiazolyl) amino doxycycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl minocycline carbamate;-   9-(Phenylthiazolyl) amino sancycline;-   9-(Adamantylthiazolyl) amino doxycycline;-   9-(Naphthyn-1-yl urea) Doxycycline 5-propanoic acid ester;-   Doxycycline 9-Thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline thiourea;-   9-(3-methyl-1-butyl) doxycycline thiourea;-   9-Phenyl doxycycline thiourea;-   9-t-Butyl doxycycline thiourea;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   9-(4′-Fluorophenyl) doxycycline thiocarbamate;-   9-(4-Methoxyphenyl) doxycycline thiocarbamate;-   9-Neopentyl minocycline thiocarbamate;-   9-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester;-   Minocycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline urea;-   9-(3-Methyl-1-butyl) minocycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl minocycline urea;-   FMOC 9-amino minocycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) minocycline urea;-   9-(4′-Fluorophenyl) minocycline carbamate;-   9-(4′-Methoxyphenyl) minocycline carbamate;-   9-BOC amino minocycline;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Ethylthiazolyl) amino minocycline;-   (4′-Fluorophenylthiazolyl) amino minocycline;-   9-(4′-Methoxyphenylthiazolyl) amino minocycline;-   9-9-(3′-Nitrophenylthiazolyl) amino minocycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl doxycycline carbamate;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Adamantylthiazolyl) amino minocycline;-   Minocycline 9-thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline thiourea;-   9-(3′-Methyl-1-butyl) minocycline thiourea;-   9-Phenyl minocycline thiourea;-   9-t-Butyl minocycline thiourea;-   9-(4′-Fluorophenyl) minocycline thiocarbamate;-   9-(4′-Methoxyphenyl) minocycline thiocarbamate;-   9-Neopentyl doxycycline thiocarbamate;-   9-(2′-Bromoethyl) doxycycline carbamate;-   9-(n-Pentyl) minocycline carbamate;-   9-(4′-Benzoylbenzoyl) amino doxycycline;-   7-(3′-Nitrophenylthiazolyl) amino sancycline;-   9-(3′-Ethoxycarbonylthiazolyl) amino doxycycline;-   7-(4′-Methylphenyl) sancycline carbamate;-   9-(4′-Trifluoromethoxyphenyl) minocycline urea;-   9-(3′,5′-diperfluorophenyl) minocycline thiourea;-   9-Prop-2′-enyl minocycline carbamate;-   9-(4′-Chloro, 2′-nitrophenyl) minocycline urea;-   9-Ethyl minocycline carbamate;-   9-n-Butyl minocycline carbamate;-   9-n-But-3-enyl minocycline carbamate;-   Doxycycline 7-carbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline urea;-   7-(3-Methyl-1-butyl) doxycycline urea;-   7-Phenyl doxycycline urea;-   7-t-Butyl doxycycline urea;-   7-Fmoc amino doxycycline;-   7-(4′-Chloro-2-trifluoromethylphenyl) doxycycline urea;-   7-(4′-Fluorophenyl) doxycycline carbamate;-   7-(4′-Methoxyphenyl) doxycycline carbamate;-   7-BOC amino doxycycline;-   7-(3′Phenylthiazolyl) amino doxycycline;-   7-(3′-Ethylthiazolyl) amino doxycycline;-   7-(4″-Fluorophenylthiazolyl) amino doxycycline;-   7-(4″-Methoxyphenylthiazolyl) amino doxycycline;-   7-(Phenylthiazolylamino)-sancycline;-   7-(3′-Nitrophenylthiazolyl) amino doxycycline;-   7-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   7-(Adamantylthiazolyl) amino doxycycline;-   Doxycycline 7-thiocarbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline thiourea;-   7-(3-Methyl-1-butyl) doxycycline thiourea;-   7-Phenyl amino doxycycline thiourea;-   7-t-butyl amino doxycycline thiourea;-   7-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   7-(4′-Fluorophenyl) doxycycline thiocarbamate;-   7-(4′-Methoxyphenyl) doxycycline thiocarbamate;-   7-(Naphthyn-1-yl) doxycycline urea 5-propanoic acid ester;-   7-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester;-   9-i-Butyl minocycline carbamate, and pharmaceutically acceptable    salts and prodrugs thereof.

The language “effective amount” of the substituted tetracycline compoundis that amount necessary or sufficient to treat or prevent atetracycline compound responsive state. The effective amount can varydepending on such factors as the size and weight of the subject, thetype of illness, or the particular substituted tetracycline compound.For example, the choice of the substituted tetracycline compound canaffect what constitutes an “effective amount”. One of ordinary skill inthe art would be able to study the aforementioned factors and make thedetermination regarding the effective amount of the substitutedtetracycline compound without undue experimentation.

The invention also pertains to methods of treatment againstmicroorganism infections and associated diseases. The methods includeadministration of an effective amount of one or more substitutedtetracycline compounds to a subject. The subject can be either a plantor, advantageously, an animal, e.g., a mammal, e.g., a human.

In the therapeutic methods of the invention, one or more substitutedtetracycline compounds of the invention may be administered alone to asubject, or more typically a compound of the invention will beadministered as part of a pharmaceutical composition in mixture withconventional excipient, i.e., pharmaceutically acceptable organic orinorganic carrier substances suitable for parenteral, oral or otherdesired administration and which do not deleteriously react with theactive compounds and are not deleterious to the recipient thereof.

In one embodiment, the invention pertains to pharmaceutical compositionswhich comprise one or more substituted tetracycline compounds of theinvention, as described above. The invention pertains to pharmaceuticalcompositions which comprise any of the substituted tetracyclinecompounds described in this application. For example, the inventionpertains to pharmaceutical compositions which comprise substitutedtetracycline compounds of both Formula (I) and Table 2. Other examplesof substituted tetracycline compounds of the invention which may beincluded in the pharmaceutical compositions of the invention include,but are not limited to:

-   Doxycycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline urea;-   9-(3-Methyl-1-butyl) doxycycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl doxycycline urea;-   FMOC 9-amino doxycycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline urea;-   9-(4′-Fluorophenyl) doxycycline carbamate;-   9-(4′-Methoxyphenyl) doxycycline carbamate;-   9-BOC amino doxycycline;-   9-(Phenylthiazolyl) amino doxycycline;-   9-(Ethylthiazolyl) amino doxycycline;-   (4-Fluorophenylthiazolyl) amino doxycycline;-   9-(4′-Methoxyphenylthiazolyl) amino doxycycline;-   9-(3′-Nitrophenylthiazolyl) amino doxycycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl minocycline carbamate;-   9-(Phenylthiazolyl) amino sancycline;-   9-(Adamantylthiazolyl) amino doxycycline;-   9-(Naphthyn-1-yl urea) Doxycycline 5-propanoic acid ester;-   Doxycycline 9-Thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) doxycycline thiourea;-   9-(3-methyl-1-butyl) doxycycline thiourea;-   9-Phenyl doxycycline thiourea;-   9-t-Butyl doxycycline thiourea;-   9-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   9-(4′-Fluorophenyl) doxycycline thiocarbamate;-   9-(4-Methoxyphenyl) doxycycline thiocarbamate;-   9-Neopentyl minocycline thiocarbamate;-   9-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester;-   Minocycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline urea;-   9-(3-Methyl-1-butyl) minocycline urea;-   9-Phenyl doxycycline urea;-   9-t-Butyl minocycline urea;-   FMOC 9-amino minocycline;-   9-(4′-Chloro-2′-trifluoromethylphenyl) minocycline urea;-   9-(4′-Fluorophenyl) minocycline carbamate;-   9-(4′-Methoxyphenyl) minocycline carbamate;-   9-BOC amino minocycline;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Ethylthiazolyl) amino minocycline;-   (4′-Fluorophenylthiazolyl) amino minocycline;-   9-(4′-Methoxyphenylthiazolyl) amino minocycline;-   9-9-(3′-Nitrophenylthiazolyl) amino minocycline;-   9-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   9-Neopentyl doxycycline carbamate;-   9-(Phenylthiazolyl) amino minocycline;-   9-(Adamantylthiazolyl) amino minocycline;-   Minocycline 9-thiocarbamic acid 9H-fluoren-9-ylmethyl ester;-   (9-(Naphthyn-1-yl) minocycline thiourea;-   9-(3′-Methyl-1-butyl) minocycline thiourea;-   9-Phenyl minocycline thiourea;-   9-t-Butyl minocycline thiourea;-   9-(4′-Fluorophenyl) minocycline thiocarbamate;-   9-(4′-Methoxyphenyl) minocycline thiocarbamate;-   9-Neopentyl doxycycline thiocarbamate;-   9-(2′-Bromoethyl) doxycycline carbamate;-   9-(n-Pentyl) minocycline carbamate;-   9-(4′-Benzoylbenzoyl) amino doxycycline;-   7-(3′-Nitrophenylthiazolyl) amino sancycline;-   9-(3′-Ethoxycarbonylthiazolyl) amino doxycycline;-   7-(4′-Methylphenyl) sancycline carbamate;-   9-(4′-Trifluoromethoxyphenyl) minocycline urea;-   9-(3′,5′-diperfluorophenyl) minocycline thiourea;-   9-Prop-2′-enyl minocycline carbamate;-   9-(4′-Chloro, 2′-nitrophenyl) minocycline urea;-   9-Ethyl minocycline carbamate;-   9-n-Butyl minocycline carbamate;-   9-n-But-3-enyl minocycline carbamate;-   Doxycycline 7-carbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline urea;-   7-(3-Methyl-1-butyl) doxycycline urea;-   7-Phenyl doxycycline urea;-   7-t-Butyl doxycycline urea;-   7-Fmoc amino doxycycline;-   7-(4′-Chloro-2-trifluoromethylphenyl) doxycycline urea;-   7-(4′-Fluorophenyl) doxycycline carbamate;-   7-(4′-Methoxyphenyl) doxycycline carbamate;-   7-BOC amino doxycycline;-   7-(3′Phenylthiazolyl) amino doxycycline;-   7-(3′-Ethylthiazolyl) amino doxycycline;-   7-(4″-Fluorophenylthiazolyl) amino doxycycline;-   7-(4″-Methoxyphenylthiazolyl) amino doxycycline;-   7-(Phenylthiazolylamino)-sancycline;-   7-(3′-Nitrophenylthiazolyl) amino doxycycline;-   7-(4′-Methyl, 5′-phenylthiazolyl) amino doxycycline;-   7-(Adamantylthiazolyl) amino doxycycline;-   Doxycycline 7-thiocarbamic acid 7H-fluoren-7-ylmethyl ester;-   7-(Naphthyn-1-yl) doxycycline thiourea;-   7-(3-Methyl-1-butyl) doxycycline thiourea;-   7-Phenyl amino doxycycline thiourea;-   7-t-butyl amino doxycycline thiourea;-   7-(4′-Chloro-2′-trifluoromethylphenyl) doxycycline thiourea;-   7-(4′-Fluorophenyl) doxycycline thiocarbamate;-   7-(4′-Methoxyphenyl) doxycycline thiocarbamate;-   7-(Naphthyn-1-yl) doxycycline urea 5-propanoic acid ester;-   7-(Naphthyn-1-yl) doxycycline thiourea 5-propanoic acid ester;-   9-i-Butyl minocycline carbamate, and pharmaceutically acceptable    salts and prodrugs thereof.

The language “pharmaceutically acceptable carrier” includes substancescapable of being coadministered with the substituted tetracyclinecompound(s), and which allow the substituted tetracycline compound toperform its intended function, e.g., treat or prevent a tetracyclinecompound responsive state. Suitable pharmaceutically acceptable carriersinclude but are not limited to water, salt solutions, alcohol, vegetableoils, polyethylene glycols, gelatin, lactose, amylose, magnesiumstearate, talc, silicic acid, viscous paraffin, perfume oil, fatty acidmonoglycerides and diglycerides, petroethral fatty acid esters,hydroxymethyl-cellulose, polyvinylpyrrolidone, etc. The pharmaceuticalpreparations can be sterilized and if desired mixed with auxiliaryagents, e.g., lubricants, preservatives, stabilizers, wetting agents,emulsifiers, salts for influencing osmotic pressure, buffers, colorings,flavorings and/or aromatic substances and the like which do notdeleteriously react with the active compounds of the invention.

The substituted tetracycline compounds of the invention that are basicin nature are capable of forming a wide variety of salts with variousinorganic and organic acids. The acids that may be used to preparepharmaceutically acceptable acid addition salts of the tetracyclinecompounds of the invention that are basic in nature are those that formnon-toxic acid addition salts, i.e., salts containing pharmaceuticallyacceptable anions, such as the hydrochloride, hydrobromide, hydroiodide,nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate,acetate, lactate, salicylate, citrate, acid citrate, tartrate,pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate,fumarate, gluconate, glucaronate, saccharate, formate, benzoate,glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate,p-toluenesulfonate and palmoate [i.e.,1,1′-methylene-bis-(2-hydroxy-3-naphthoate)] salts. Although such saltsmust be pharmaceutically acceptable for administration to a subject,e.g., a mammal, it is often desirable in practice to initially isolate atetracycline compound of the invention from the reaction mixture as apharmaceutically unacceptable salt and then simply convert the latterback to the free base compound by treatment with an alkaline reagent andsubsequently convert the latter free base to a pharmaceuticallyacceptable acid addition salt. The acid addition salts of the basecompounds of this invention are readily prepared by treating the basecompound with a substantially equivalent amount of the chosen mineral ororganic acid in an aqueous solvent medium or in a suitable organicsolvent, such as methanol or ethanol. Upon careful evaporation of thesolvent, the desired solid salt is readily obtained.

The substituted tetracycline compounds of the invention that are acidicin nature are capable of forming a wide variety of base salts. Thechemical bases that may be used as reagents to prepare pharmaceuticallyacceptable base salts of those substituted tetracycline compounds of theinvention that are acidic in nature are those that form non-toxic basesalts with such compounds. Such non-toxic base salts include, but arenot limited to those derived from such pharmaceutically acceptablecations such as alkali metal cations (e.g., potassium and sodium) andalkaline earth metal cations (e.g., calcium and magnesium), ammonium orwater-soluble amine addition salts such asN-methylglucamine-(meglumine), and the lower alkanolammonium and otherbase salts of pharmaceutically acceptable organic amines. Thepharmaceutically acceptable base addition salts of tetracyclinecompounds of the invention that are acidic in nature may be formed withpharmaceutically acceptable cations by conventional methods. Thus, thesesalts may be readily prepared by treating the tetracycline compound ofthe invention with an aqueous solution of the desired pharmaceuticallyacceptable cation and evaporating the resulting solution to dryness,preferably under reduced pressure. Alternatively, a lower alkyl alcoholsolution of the substituted tetracycline compound of the invention maybe mixed with an alkoxide of the desired metal and the solutionsubsequently evaporated to dryness.

The preparation of other tetracycline compounds of the invention notspecifically described in the foregoing experimental section can beaccomplished using combinations of the reactions described above thatwill be apparent to those skilled in the art.

The substituted tetracycline compounds of the invention andpharmaceutically acceptable salts thereof can be administered via eitherthe oral, parenteral or topical routes. In general, these compounds aremost desirably administered in effective dosages, depending upon theweight and condition of the subject being treated and the particularroute of administration chosen. Variations may occur depending upon thespecies of the subject being treated and its individual response to saidmedicament, as well as on the type of pharmaceutical formulation chosenand the time period and interval at which such administration is carriedout.

The pharmaceutical compositions of the invention may be administeredalone or in combination with other known compositions for treatingtetracycline responsive states in a mammal. Preferred mammals includepets (e.g., cats, dogs, ferrets, etc.), farm animals (cows, sheep, pigs,horses, goats, etc.), lab animals (rats, mice, monkeys, etc.), andprimates (chimpanzees, humans, gorillas). The language “in combinationwith” a known composition is intended to include simultaneousadministration of the composition of the invention and the knowncomposition, administration of the composition of the invention first,followed by the known composition and administration of the knowncomposition first, followed by the composition of the invention. Any ofthe therapeutically composition known in the art for treatingtetracycline responsive states can be used in the methods of theinvention.

The substituted tetracycline compounds of the invention may beadministered alone or in combination with pharmaceutically acceptablecarriers or diluents by any of the routes previously mentioned, and theadministration may be carried out in single or multiple doses. Forexample, the novel therapeutic agents of this invention can beadministered advantageously in a wide variety of different dosage forms,i.e., they may be combined with various pharmaceutically acceptableinert carriers in the form of tablets, capsules, lozenges, troches, hardcandies, powders, sprays, creams, salves, suppositories, jellies, gels,pastes, lotions, ointments, aqueous suspensions, injectable solutions,elixirs, syrups, and the like. Such carriers include solid diluents orfillers, sterile aqueous media and various non-toxic organic solvents,etc. Moreover, oral pharmaceutical compositions can be suitablysweetened and/or flavored. In general, the therapeutically-effectivecompounds of this invention are present in such dosage forms atconcentration levels ranging from about 5.0% to about 70% by weight.

For oral administration, tablets containing various excipients such asmicrocrystalline cellulose, sodium citrate, calcium carbonate, dicalciumphosphate and glycine may be employed along with various disintegrantssuch as starch (and preferably corn, potato or tapioca starch), alginicacid and certain complex silicates, together with granulation binderslike polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally,lubricating agents such as magnesium stearate, sodium lauryl sulfate andtalc are often very useful for tabletting purposes. Solid compositionsof a similar type may also be employed as fillers in gelatin capsules;preferred materials in this connection also include lactose or milksugar as well as high molecular weight polyethylene glycols. Whenaqueous suspensions and/or elixirs are desired for oral administration,the active ingredient may be combined with various sweetening orflavoring agents, coloring matter or dyes, and, if so desired,emulsifying and/or suspending agents as well, together with suchdiluents as water, ethanol, propylene glycol, glycerin and various likecombinations thereof.

For parenteral administration (including intraperitoneal, subcutaneous,intravenous, intradermal or intramuscular injection), solutions of asubstituted tetracycline compound of the present invention in eithersesame or peanut oil or in aqueous propylene glycol may be employed. Theaqueous solutions should be suitably buffered (preferably pH greaterthan 8) if necessary and the liquid diluent first rendered isotonic.These aqueous solutions are suitable for intravenous injection purposes.The oily solutions are suitable for intraarticular, intramuscular andsubcutaneous injection purposes. The preparation of all these solutionsunder sterile conditions is readily accomplished by standardpharmaceutical techniques well known to those skilled in the art. Forparenteral application, examples of suitable preparations includesolutions, preferably oily or aqueous solutions as well as suspensions,emulsions, or implants, including suppositories. Substitutedtetracycline compounds may be formulated in sterile form in multiple orsingle dose formats such as being dispersed in a fluid carrier such assterile physiological saline or 5% saline dextrose solutions commonlyused with injectables.

Additionally, it is also possible to administer the substitutedtetracycline compounds of the present invention topically when treatinginflammatory conditions of the skin. Examples of methods of topicaladministration include transdermal, buccal or sublingual application.For topical applications, therapeutic compounds can be suitably admixedin a pharmacologically inert topical carrier such as a gel, an ointment,a lotion or a cream. Such topical carriers include water, glycerol,alcohol, propylene glycol, fatty alcohols, triglycerides, fatty acidesters, or mineral oils. Other possible topical carriers are liquidpetrolatum, isopropylpalmitate, polyethylene glycol, ethanol 95%,polyoxyethylene monolauriate 5% in water, sodium lauryl sulfate 5% inwater, and the like. In addition, materials such as anti-oxidants,humectants, viscosity stabilizers and the like also may be added ifdesired.

For enteral application, particularly suitable are tablets, dragees orcapsules having talc and/or carbohydrate carrier binder or the like, thecarrier preferably being lactose and/or corn starch and/or potatostarch. A syrup, elixir or the like can be used wherein a sweetenedvehicle is employed. Sustained release compositions can be formulatedincluding those wherein the active component is protected withdifferentially degradable coatings, e.g., by microencapsulation,multiple coatings, etc.

In addition to treatment of human subjects, the therapeutic methods ofthe invention also will have significant veterinary applications, e.g.for treatment of livestock such as cattle, sheep, goats, cows, swine andthe like; poultry such as chickens, ducks, geese, turkeys and the like;horses; and pets such as dogs and cats. Also, the compounds of theinvention may be used to treat non-animal subjects, such as plants.

It will be appreciated that the actual preferred amounts of activecompounds used in a given therapy will vary according to the specificcompound being utilized, the particular compositions formulated, themode of application, the particular site of administration, etc. Optimaladministration rates for a given protocol of administration can bereadily ascertained by those skilled in the art using conventionaldosage determination tests conducted with regard to the foregoingguidelines.

In general, compounds of the invention for treatment can be administeredto a subject in dosages used in prior tetracycline therapies. See, forexample, the Physicians' Desk Reference. For example, a suitableeffective dose of one or more compounds of the invention will be in therange of from 0.01 to 100 milligrams per kilogram of body weight ofrecipient per day, preferably in the range of from 0.1 to 50 milligramsper kilogram body weight of recipient per day, more preferably in therange of 1 to 20 milligrams per kilogram body weight of recipient perday. The desired dose is suitably administered once daily, or severalsub-doses, e.g. 2 to 5 sub-doses, are administered at appropriateintervals through the day, or other appropriate schedule.

It will also be understood that normal, conventionally known precautionswill be taken regarding the administration of tetracyclines generally toensure their efficacy under normal use circumstances. Especially whenemployed for therapeutic treatment of humans and animals in vivo, thepractitioner should take all sensible precautions to avoidconventionally known contradictions and toxic effects. Thus, theconventionally recognized adverse reactions of gastrointestinal distressand inflammations, the renal toxicity, hypersensitivity reactions,changes in blood, and impairment of absorption through aluminum,calcium, and magnesium ions should be duly considered in theconventional manner.

EXEMPLIFICATION OF THE INVENTION

The following example illustrates various methods of synthesizing 9- and7-substituted tetracycline compounds in accordance with the invention.Other compounds of the invention can be synthesized using methodsdescribed herein and/or methods known in the art.

Example 1 Synthesis of 9-Amino-Substituted Tetracycline Compounds

To an ice cold solution of doxycycline (2 g, 4.15 mmol) in 30 ml ofconcentrated H₂SO₄, potassium nitrate (0.5 g; 1.2 eq) was addedportion-wise. The reaction mixture was stirred for 1½ hours. The acidsolution was then added to ˜200 ml of ice water. The precipitated yellowmaterial was filtered. The filtered material was dissolved in methanol.After the methanol was evaporated, the product was extracted withn-butanol. The organic phase was washed with saturated NaHCO₃ twice andthe solvent removed in vacuo.

The resulting product was dissolved in 50 ml of methanol and 1 ml ofconcentrated HCl and hydrogenated on Pd/C to yield the 9- and7-aminodoxycycline positional isomers as an off-yellow solid. Theisomers can be purified by HPLC and other techniques known in the art.

9-Aminodoxycycline 9-amino-6-α-deoxy-5-hydroxytetracyline

MS (M+H): 460 ¹HNMR (CD₃OD): δ 7.62 (d, 1H, H-8); 7.14 (d, 1H, H-7);4.42 (s, 1H, H-4); 3.6 (dd, 1H, H-5); 2.98, 2.90 (each s, each 3H,NMe₂); 2.84 (d, 1H, H-4a); 2.72 (m, 1H, H-6); 2.59 (dd, 1H, H-5a); 1.51(d, 3H, CH₃—C₆).

General Synthesis of Mixed Urea of 9- or 7-Amino-6-α-tetracyclineCompound:

In one portion, 1.2 equivalents of an isocyanate was added to a solutionof 9-amino tetracycline compound in DMF and two equivalents ofdiisoproplyethylamine. The reaction mixture was stirred at roomtemperature for several hours (usually 4 hours to overnight). Thedesired product was isolated by C18 reverse-phase column chromatography.The 7-amino tetracycline compound urea can be synthesized using thesimilar methodology with the 7-amino tetracycline compound as thestarting material.

The following compounds were made using the above procedure.

Compound B: 9-Aminonaphthyl Doxycycline urea 1-Napthyl,9-amino-6-α-deoxy-5-hydroxy-tetracycline mixed urea

¹HNMR (CD₃OD): δ 7.9 (d, 1H, H-8); 7.8-7.4 (m, 7H, aryl); 6.9 (bd, 1H,H-7); 4.42 (s, 1H, H-4); 3.6 (d, 1H, H-5); 2.88, 2.77 (each s, each 3H,NMe₂); 2.84 (d, 1H, H-4a); 2.72 (m, 1H, H-6); 2.59 (dd, 1H, H-5a); 1.31(d, 3H, CH₃—C₆). MS (M+H): calc. 629.63; Found 629.16.

Compound E: 9-Aminophenyl Doxycycline Urea Phenyl,9-amino-α-deoxy-5-hydroxy-tetracycline mixed urea

¹HNMR (CD₃OD): δ 8.25 (d, 1H, H-8); 7.45 (d, 2H, aryl); 7.29 (m, 2H,aryl); 7.0 (d, 1H, aryl); 6.9 (d, 1H, H-7); 4.25 (s, 1H, H-4); 3.6 (dd,1H, H-5); 2.85 (bs, 6H, NMe₂); 2.84 (d, 1H, H-4a); 2.72 (m, 1H, H-6);2.58 (dd, 1H, H-5a); 1.54 (d, 3H, CH₃—C₆). MS (M+H): calc. 579.57; Found579.15.

Compound F: 9-Amino-t-butyl doxycycline urea Tert-butyl,9-amino-6-α-deoxy-5-hydroxy-tetracycline mixed urea

¹HNMR (CD₃OD); δ 8.1 (d, 1H, H-8); 6.84 (d, 1H, H-7); 4.31 (s, 1H, H-4);3.55 (dd, 1H, H-5); 2.91 (bs, 6H, NMe₂); 2.71-2.57 (m, 3H, H-4a, H-6,H-5a); 1.51 (d, 3H, CH₃—C₆); 1.36 (s, 9H, tert butyl); MS (M+H): calc.559.58; Found: 559.19.

Compound I: 9-(4′-Chloro, 2′-trifluoromethylphenyl amino)-Doxycyclineurea 4-Chloro, 2-trifluoromethylphenyl,9-amino-6-α-deoxy-5-hydroxy-tetracycline mixed urea

¹HNMR (CD₃OD): δ 8.28 (d, 1H, H-8); 7.89 (d, 1H, aryl); 7.66 (s, 1H,aryl); 7.58 (d, 1H, aryl); 6.93 (d, 1H, H-7); 4.42 (s, 1H, H-4); 3.56(dd, 1H, H-5); 2.98 & 2.90 (each s, 3H, NMe₂); 2.84 (d, 2H, H-4a); 2.72(m, 1H, H-6); 2.56 (dd, 1H, H-5a); 1.52 (d, 3H, CH₃—C₆). MS (M+O): calc.

Compound AJ: 9-(3,5-Bis (Trifluoromethylphenyl)Amino) Doxycycline urea3,5-bis (trifluoromethyl phenyl),9-amino-6-α-deoxy-5-hydroxy-tetracycline mixed urea

General Synthesis of Carbamates of 9- or 7-amino-doxycycline:

In a single portion, 1.2 equivalents of chloroformate was added to asolution of 9-aminodoxycycline in DMF in the presence of two equivalentof diisopropylethylamine. The reaction mixture was stirred at roomtemperature for several hours. The desired product was isolated by C18reverse-phase column chromatography. The 7-amino tetracycline compoundcarbamate can be synthesized using the similar methodology with the7-amino tetracycline compound as the starting material. The followingcarbamates were synthesized using the general synthesis outlined above.

Compound A: FMOC-9-Amino Doxycycline N-Fluorenylmethyloxycarbonyl9-amino-6-α-deoxy-5-hydroxy-tetracycline

¹HNMR (CD₃OD) δ 7.9 (bd, 1H, H-8), 7.69 (d, 2H, aryl); 7.56 (m, 2H,aryl); 7.29 (m, 4H, aryl); 6.8 (d, 1H, H-7); 4.35 (d, 2H, CH₂) 4.30 (s,1H, H-4); 4.15 (m, 1H, CH); 3.5 (dd, 1H, H-5); 2.85 (bd, 6H, NMe₂); 2.83(d, 1H, H-4a); 2.73 (m, 1H, H-6a); 2.57 (dd, 1H, H-5a); 1.40 (d, 3H,CH₃—C₆); MS (M+H): calc. 682.69; Found: 682.

Compound K: 9-(Fluorophenyl) Doxycycline CarbamateN-p-Fluorophenyloxycarbonyl 9-amino-6-α-deoxy-5-hydroxy tetracycline)

¹HNMR (CD₃OD) δ: 7.92 (d, 1H, H-8); 7.11-6.98 (m, 4H, aryl); 6.85 (d,1H, H-7); 4.34 (s, 1H, H-4); 3.42 (dd, 1H, H-5); 2.86 (bd, 6H, NMe₂);2.83 (d, 1H, H-5a); 2.72 (m, 1H, H-6); 2.56 (dd, 1H, H-5a); 1.43 (d, 3H,CH₃—C₆). MS (M+H): calc. 598.55; Found: 598.50

Compound L: 9-(4-Methoxyphenyl) Doxycycline CarbamateN-p-methoxyphenyloxycarbonyl 9-amino-6-α-deoxy-5-hydroxy tetracycline

¹HNMR (CD₃OD): δ 7.92 (bd, 1H, H-8); 6.97 (d, 2H, aryl); 6.82 (m, 3H,H-7 and aryl); 4.36 (s, 1H, H-4); 3.66 (s, 3H, OMe); 3.4 (d, 1H, H-5);2.86 (bd, 6H, NMe₂); 2.83 (d, 1H, H-4a); 2.78 (m, 1H, H-6); 2.56 (dd,1H, H-5a); 1.43 (d, 3H, CH₃—C₆). MS (M+H): calc. 610.58; Found: 610.50.

Compound M: 9-BOC-Amino Doxycycline N-tert-butyloxycarbonyl9-amino-6-α-deoxy-5-hydroxy-tetracycline

¹HNMR (CD₃OD): δ 8.04 (d, 1H, H-8); 6.92 (d, 1H, H-7); 4.05 (s, 1H,H-4); 3.62 (dd, 1H, H-5); 2.82 (bs, 6H, NMe₂); 2.83 (d, 1H, H-4a); 2.74(m, 1H, H-6); 2.57 (dd, 1H, H-5a); 1.52 (bs, 12H, CH₃—C₆+tert-butyl); MS(M+H): calc. 560.57; found: 560.16.

Compound AP: 9-Neopentyl Minocycline Carbamate N-neopentyloxycarbonyl9-amino-6-α-deoxy-5-hydroxy-tetracycline

¹HNMR (CD₃OD): δ 7.9 (d, 1H, H-8); 6.9 (d, 1H, H-7); 4.36 (s, 1H, H-4);3.77 (s, 2H, neopentyl CH₂); 3.6 (dd, 1H, H-5); 2.88, 2.81 (bs, 6H,NMe₂); 2.84 (d, 1H, H-4a); 2.72 (m, 1H, H-6); 2.59 (dd, 1H, H-5a); 1.45(d, 3H, CH₃—C₆); 0.89 (s, 9H, neopentyl CH₃). MS (M+H): calc. 587.63;Found: 587.5.

Synthesis of 2-Aminothiazole Derivatives of Tetracycline Compounds

Fluorenylmethyloxycarbonyl chloride (1.80 g; 5 mmol) was dissolved in 10ml of ethyl acetate. This solution was added drop-wise to a suspensionof potassium thiocyanate (1.2 eq) in 10 ml of ethyl acetate at 0° andunder nitrogen atmosphere. The reaction mixture was left stirringovernight. The reaction mixture was then filtered over celite pad toremove residual salts, and the ethyl acetate was removed in vacuo. Thecrude yellow material was used to synthesize the compounds below.

Compound AT: 9-FMOC-Amino Doxycycline thiocarboxamide3-(Fluorenylmethyloxycarbonyl)-1-(9-amino-6-α-deoxy-5-hydroxytetracycline)-thio carboxamide

To 300 mg (0.65 mmol) of 9-amino doxycycline in 3 ml of DMF and in thepresence of 227 μl (2 eq) of diisopropylethylamine, was added in oneportion of 182 mg of fluorenylmethyloxy-carbonyl isothiocyanate in 1 mlof DMF. The reaction mixture was stirred at room temperature for 5hours. The desired product was isolated through C18 reverse-phase columnchromatography.

¹HNMR (CD₃OD): δ 8.82 (d, 1H, H-8); 7.82 (d, 2H, aryl); 7.72 (d, 2H,aryl); 7.4 (m, 4H, aryl); 6.92 (d, 1H, H-7); 4.56 (d, 2H, CH₂); 4.44 (s,1, H-4); 4.30 (m, 1H, CH); 3.6 (dd, 1H, H-5); 2.98 (bd, 6H, NMe₂); 2.84(d, 1H, H-4a); 2.73 (m, 1H, H-6); 2.56 (dd, 1H, H-5a); 1.54 (d, 3H,CH₃—C₆). MS (M+H): calc. 741.78; Found: 741.28.

6-α-deoxy-5-hydroxy-tetracycline thiourea

300 mg (0.405 mmol) of3-(fluorenylmethyloxycarbonyl)-1-(9-amino-6-α-deoxy-5-hydroxytetracycline)-thio carboxamide was deblocked in a solution of 2%piperidine, 2% DBU in DMF at room temperature. The solvent was thenevaporated in vacuo after acidification with concentrated HCl. Theresidue was dissolved in 1 ml of MeOH and added dropwise to 100 ml ofcold ethyl acetate. The precipitated yellow solid was filtered anddried.

¹HNMR (CD₃OD); δ 7.90 (d, 1H, H-8); 6.95 (d, 1H, H-7); 4.48 (s, 1H,H-4); 3.57 (dd, 1H, H-5); 3.04, 2.92 (two s, each 3H, NMe₂); 2.84 (d,1H, H-4a); 2.7 (m, 1H, H-6); 2.6 (dd, 1H, H-5a); 1.54 (d, 3H, CH₃—C₆).MS (M+H): calc. 519.54; Found: 519.20.

General Synthesis of 7- or 9-(2′-thiazolyl amino) Tetracycline Compounds

In one portion, the appropriate α-bromo ketone was added to atetracycline compound thiourea in a mixture of DMF/Dioxane (3:1) and anequivalent amount of diisopropylethylamine. The reaction mixture wasleft stirring overnight. The thiazole product was isolated through C18reverse-phase column chromatography. The following thiazole compoundswere synthesized using the method described above.

Compound N: 9-(4′-Phenyl thiazolyl)-amino Doxycycline2[9(amino-6-α-deoxy-5-hydroxy tetracycline)]-4-phenyl thiazole

¹HNMR (CD₃OD): δ 8.25 (d, 1H, H-8); 7.8 (d, 2H, aryl); 7.45 (m, 3H,aryl); 7.1 (s, 1H, vinyl); 7.09 (d, 1H, H-7); 4.46 (s, 1H, H-4); 3.6(dd, 1H, H-5); 2.91 & 2.88 (Two s, each 3H, NMe₂); 2.84 (d, 1H, H-4a);2.7 (m, 1H, H-6); 2.57 (dd, 1H, H-5a); 1.6 (d, 3H, CH₃—C₆). MS (M+H):calc. 619.66; Found: 619.19.

Compound O: 9-(4′-Ethyl thiazolyl)-amino Doxycycline2[9-(amino-6-α-deoxy-5-hydroxy tetracycline)-4-ethyl]thiazole

¹HNMR (CD₃OD): δ 7.9 (d, 1H, H-8); 7.05 (d, 1H, H-7); 6.55 (s, 1H,vinyl); 4.46 (s, 1H, H-4); 3.57 (dd, 1H, H-5a); 2.96 (bs, 6H, NMe₂),2.87 (d, 1H, H-4a); 2.7 (m, 1H, H-6); 2.6 (m, 3H, H-5a and CH₂ of theethyl); 1.59 (d, 3H, CH₃—C₆); 1.28 (d, 3H, CH₃ of the ethyl); MS (M+H):calc. 571.62; Found: 571.2.

Compound Q: 9-(4-Methoxyphenylthiazolyl)-amino Doxycycline2[(9-amino-6-α-deoxy-5-hydroxy tetracycline)]4-(4-methoxyphenyl)thiazole

¹HNMR (CD₃OD): δ 7.94 (d, 1H, H-8); 7.68 (d, 2H, aryl); 7.10 (d, 1H,H-7); 7.06 (d, 2H, aryl; 4.49 (s, 1H, H-4); 3.86 (s, 3H, OMe); 3.56 (dd,1H, H-5); 3.0 & 2.94 (two s, each 3H, NMe₂); 2.87 (d, 1H, H-4a); 2.73(m, 1H, H-6); 1.63 (d, 3H, CH₃—C₆). MS (M+H): calc. 649.68; Found:649.15.

Compound R: 9-(3-Nitrophenylthiazolyl)-amino Doxycycline2[9-(amino-6-α-deoxy-5-hydroxy tetracycline)]-4-(3-nitrophenyl)thiazole)

¹HNMR (CD₃OD): δ 8.6 (m, 2H, aryl); 8.2 (d, 1H, H-8); 8.1 (d, 1H, aryl);7.6 (m, 1H, aryl); 7.3 (s, 1H, vinyl); 6.9 (d, 1H, H-7); 4.44 (s, 1H,H-4); 3.57 (dd, 1H, H-5); 3.0 & 2.91 (two s, each 3H, NMe₂); 2.84 (s,1H, H-4a); 2.7 (m, 1H, H-6); 2.57 (dd, 1H, H-5a); 1.56 (d, 3H, CH₃—C₆).MS (M+H): calc. 664.66; Found: 664.60.

Compound S: 9-(4-Methyl-5-phenylthiazolyl)-amino Doxycycline2[9(amino-6-α-deoxy-5-hydroxy tetracycline)]-4-phenyl-5-methyl thiazole

¹HNMR (CD₃OD): δ 7.98 (d, 1H, H-8); 7.6-7.4 (m, 5H, aryl); 7.05 (d, 1H,H-7); 4.46 (s, 1H, H4); 3.57 (dd, 1H, H-5); 2.95 (bs, 6H, NMe₂); 2.87(d, 1H, H-4a); 2.7 (m, 1H, H-6); 2.6 (dd, 1H, H-5a); 2.36 (s, 3H, CH₃):1.57 (d, 3H, CH₃—C₆). MS (M+H): calc. 633.68; Found: 663.61.

Compound U: (9-(N,N-Dimethyl Glycyl)-Doxycycline)

NN-Dimethylglycine (1.2 mmol) is dissolved in DMF (5 mL) andO-Benzotriazol-1-yl-N,N, N′,N′,-tetramethyluronium hexafluorophosphate(HBTU, 1.2 mmol) is added. The solution is then stirred for 5 minutes atroom temperature. To this solution, 9-amino doxycycline (1 mmol) isadded, followed by the addition of diisopropylethyl amine (DIEA, 1.2mmol). The reaction is then stirred at room temperature for 2 hours. Thesolvent, DMF, is removed under vaccum. The crude material is dissolvedin 5 mL of MeOH and filtered using autovials and is purified usingpreparative HPLC. The structure of the product is characterized using 1HNMR, HPLC, and MS.

Example 2 In Vitro Minimum Inhibitory Concentration (MIC) Assay

The following assay was used to determine the efficacy of tetracyclinecompounds against common bacteria (E. coli, S. aureus, E. hirae, and E.faecalis). 2 mg of each compound was dissolved in 100 μl of DMSO. Thesolution was then added to cation-adjusted Mueller Hinton broth (CAMHB),which resulted in a final compound concentration of 200 μg per ml. Thetetracycline compound solutions were diluted to 50 μL volumes, with atest compound concentration of 0.098 μg/ml. Optical density (OD)determinations were made from fresh log-phase broth cultures of the teststrains. Dilutions were made to achieve a final cell density of about5×10⁵ CFU/ml.

50 μl of the cell suspensions were added to each well of the microtiterplates. The final cell density was approximately 5×10⁵ CFU/ml. Theseplates were incubated at 35° C. in an ambient air incubator forapproximately 18 hr.

The plates were read with a microplate reader and were visuallyinspected when necessary. The MIC is defined as the lowest concentrationof the tetracycline compound that inhibits growth. In Table 2, *indicates good inhibition of the growth of a particular organism, * *indicates inhibition of growth at a lower concentration, and * * *indicates very good inhibition of growth. Certain substitutedtetracycline compounds of the invention had MIC's less than about 10μg/ml. Other substituted tetracycline compounds of the invention hadMIC's of less than about 5 μg/mL, and still other compounds had MIC'sless than about 1 μg/mL.

TABLE 2 ID STRUCTURE NAME S. aureus E. hirae E. coli E. faecalis A

FMOC-9-amino Doxycycline *** *** * *** B

9-Naphth-1-yl doxycycline urea ** ** ** *** C

9-(3-′-methyl butyl) Doxycycline urea ** NT ** ** D

9-(Naphth-1-yl) doxycycline urea 5- propanoic acid ester ** NT ** ** E

9-Phenyl Doxycycline urea ** * ** *** F

9-t-butyl doxycycline urea ** ** * ** I

9-(4′-chloro, 2′- perfluoromethyl)-doxycycline urea ** NT ** ** K

9(4′-Fluorophenyl) doxycycline carbamate * * * * L

9(4′-Methoxyphenyl) doxcycline carbamate * * * * M

9-BOC-amino doxycycline ** ** ** ** N

9-(phenylthiazolyl)amino doxycycline *** NT * *** O

9-(ethyl thiazolyl) amino doxycycline *** NT * ** P

9-(4′- Fluorophenylthiazolyl) amino doxycycline * NT * ** Q

9 (4′-Methoxyphenyl thiazolyl)-amino doxycycline ** NT * ** R

9(3′-Nitrophenyl- thiazolyl)-amino doxycycline *** *** * *** S

9 (4′-Methyl, 3′- phenylthiazolyl)-amino doxycycline ** NT * *** T

9-(Adamantyl thiazolyl) amino-doxycycline * * * * U

9-(N,N-Dimethyl glycyl)-doxycycline * * * NT V

9-(N,N-Dimethylamino- glycyl) minocycline NT NT NT NT W

9-propyl doxycycline urea ** * ** ** X

9-(-4′-chlorophenyl sulfonyl) doxycycline urea ** * * ** Y

9-valine doxycycline urea * * * * Z

9-Cholesterol doxycycline carbamate * * * * AA

9-(2′,2′-dimethylpropyl) doxycycline carbamate ** ** ** ** AB

9-Tolyl doxcycline carbamate * * * * AC

9-Naphthyl doxycycline thiourea ** ** * ** AD

9(4′- Chloromethylphenyl) doxycycline urea ** ** * ** AE

9(4′-Chloromethyl, 2′- trifluoromethylphenyl) doxycycline urea ** ** **** AF

9 (4-chloro,2- trifluoromethylphenyl) minocycline urea ** *** * *** AG

9-Naphthyl minocycline urea ** ** ** ** AH

9-Dansyl-phenyl doxycycline thiourea * * * * AI

9-DABF-phenyl doxycycline thiourea ** *** * *** AJ

9(3,5-Bis (trifluoromethyl)phenyl doxycycline urea * * * * AK

8-Chloro-9-N,N- Dimethylamino glycyl doxycycline * * * * AL

9-Formylamino doxycycline ** * ** *** AM

9-Propenyl doxycycline carbamate * * ** *** AN

9-Bromoethyl doxycycline carbamate ** ** ** *** AO

9-Acetamide doxycycline * * * ** AP

9-(2′,2′-dimethyl propyl) minocycline carbamate ** ** * ** AQ

9-Isopropenyl minocycline carbamate * * * * AR

9-(4′- Benzoylbenzoyl)amino doxcycline ** ** * ** AS

9-BOC-amino minocycline ** ** * ** AT

3-FMOC-9-amino doxycycline-thiourea NT NT NT NT AU

9-(Phenylthiazolyl)amino doxycycline *** ** * ** AV

9(4-Diethylaminophenyl thiazolyl)-amino doxycycline * NT * * AW

9(Biphenylthiazolyl) amino-doxycycline * * * * AX

7-(3′- Nitrophenylthiazolyl) amino sancycline ** *** * *** AY

9-(Ethoxycarbonyl- thiazolyl) amino doxycycline ** ** * * AZ

7-(4′-Methoxyphenyl) sancycline carbamate ** ** * ** BA

7-(4′-Methylphenyl) Sancycline Carbamate *** *** * ** BB

9-(Naphth-1-yl) minocycline thiourea ** ** * ** BC

9-(Phenyl) minocycline urea ** ** ** ** BD

9-(4′-phenyl) minocycline urea ** ** * ** BE

9-(4′-methoxyphenyl) minocycline urea * ** ** ** BF

9-(4′- trifluoromethoxyphenyl) minocycline urea ** ** ** ** BG

9-(Benzoyl) Minocycline urea ** ** * ** BH

9-(2′, 5′- diperfluoromethyl phenyl) minocycline thiourea ** ** ** ** BI

9-(4′-Nitrophenyl)- minocycline thiourea ** ** * ** BJ

9-(prop-2-enyl) minocycline carbamate ** ** * ** BK

9-(4′-Fluoro-3′- nitrophenyl)-minocycline urea ** ** * ** BL

9-(4′-Chloro-2′- nitrophenyl)-minocycline urea ** ** ** ** BM

9-(3′-Fluorophenyl) minocycline urea ** ** * ** BN

9-Phenyl minocycline thiocarbamate * * * * BO

9-(4′-Bromophenyl)- minocycline carbamate * * * * BP

9-(4′-Chlorophenyl) minocycline carbamate * * * * BQ

9-(Ethyl)-minocycline carbamate *** ** ** ** BR

9-(n-Butyl)-minocycline carbamate ** ** ** ** BS

9-(Ethyl)-minocycline thiocarbamate ** ** * * BT

9-(But-3-enyl) minocycline carbamate ** ** ** ** BU

9-(Phenyl)-minocycline carbamate * * * * BV

9-(isobutyl)-minocycline carbamate ** ** ** **

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures described herein. Such equivalents are considered tobe within the scope of the present invention and are covered by thefollowing claims. The contents of all references, patents, and patentapplications cited throughout this application are hereby incorporatedby reference. The appropriate components, processes, and methods ofthose patents, applications and other documents may be selected for thepresent invention and embodiments thereof.

1. A substituted tetracycline compound, wherein said compound is of theformula:

wherein: X is CR^(6′)R⁶; R² is hydrogen; R⁴ and R^(4′) are each alkyl;R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen; R⁵ is hydrogen orhydroxyl; R⁶ and R^(6′) are each independently hydrogen or alkyl; R⁷ ishydrogen or NR^(7c)C(═W′)WR^(7a); R⁸ is hydrogen; R⁹ is hydrogen orNR^(9c)C(═Z′)ZR^(9a); Z is O; Z′ is O or S; R^(9a) is substituted alkyl,substituted or unsubstituted alkenyl, substituted or unsubstitutedalkynyl, substituted or unsubstituted alkoxy, substituted orunsubstituted arylsulfonyl, substituted or unsubstituted alkoxycarbonyl,substituted or unsubstituted arylcarbonyl, or substituted orunsubstituted phenyl, wherein said substituted alkyl is substituted withhalogen, amino, hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl,arylcarbonyloxy, alkoxycarbonylamino, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, aminoalkyl, arylalkylcarbonyl, alkenylcarbonyl,alkoxycarbonyl, silyl, aminocarbonyl, alkylthiocarbonyl, phosphate,aralkyl, phosphonato, phosphinato, cyano, acylamino, amido, imino,sulfhydryl, alkylthio, sulfate, arylthio, thiocarboxylate,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro, cyano, azido,heterocyclyl, alkylaryl, aryl or heteroaryl; further wherein saidsubstituted alkenyl, substituted alkynyl, substituted alkoxy substitutedarylsulfonyl, substituted alkoxycarbonyl, substituted arylcarbonyl, orsubstituted phenyl is substituted with halogen, amino, alkyl, alkenyl,alkynyl, hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl,arylcarbonyloxy, alkoxycarbonylamino, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, aminoalkyl, arylalkylcarbonyl, alkenylcarbonyl,alkoxycarbonyl, silyl, aminocarbonyl, alkylthiocarbonyl, phosphate,aralkyl, phosphonato, phosphinato, cyano, acylamino, amido, imino,sulfhydryl, alkylthio, sulfate, arylthio, thiocarboxylate,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro, cyano, azido,heterocyclyl, alkylaryl, aryl or heteroaryl; R^(9c) is hydrogen; W isCR^(7d)R^(7e), NR^(7b) or O; W′ is O or S; R^(7a), R^(7b), R^(7c),R^(7d), and R^(7e) are each independently hydrogen, alkyl, alkenyl,alkynyl, alkoxy, arylsulfonyl, alkoxycarbonyl, arylcarbonyl, alkylamino,phenyl or absent; or a pharmaceutically acceptable salt thereof,provided that R⁹ is not hydrogen when R⁷ is hydrogen.
 2. The compound ofclaim 1, wherein R⁴ and R^(4′) are each methyl.
 3. The compound of claim2, wherein R⁵ is hydrogen.
 4. The compound of claim 3, wherein X is CH₂,and R⁷ is hydrogen.
 5. The compound of claim 2, wherein R⁵ is hydroxyland X is CHR⁶.
 6. The compound of claim 5, wherein R⁶ is CH₃.
 7. Thecompound of claim 1, wherein R⁹ is NR^(9c)C(═Z′)ZR^(9a).
 8. The compoundof claim 7, wherein Z′ is oxygen.
 9. The compound of claim 7, wherein Z′is sulfur.
 10. The compound of claim 7, wherein R^(9a) is selected fromthe group consisting of substituted alkyl, substituted or unsubstitutedalkynyl, or substituted or unsubstituted phenyl.
 11. The compound ofclaim 10, wherein said substituted alkyl is substituted with one or moresubstituents selected from the group consisting of alkoxycarbonyl,amino, arylcarbonyl, halogen, hydroxy, alkylamino, alkoxy, or aryl. 12.The compound of claim 10, wherein said substituted alkyl is substitutedwith an aryl group.
 13. The compound of claim 12, wherein said arylgroup is phenyl.
 14. The compound of claim 10, wherein said substitutedalkyl is substituted with one or more halogens.
 15. The compound ofclaim 14, wherein said halogen is bromine.
 16. The compound of claim 1,wherein R^(9a) is substituted or unsubstituted phenyl.
 17. The compoundof claim 7, wherein R^(9a) comprises the group:


18. The compound of claim 16, wherein said phenyl is substituted withone or more substituents selected from the group consisting of alkyl,alkenyl, alkynyl, aryl, alkoxy, aryloxy, alkylcarbonyl, arylcarbonyl,alkoxycarbonyl, aryloxycarbonyl, amido, halogen, nitro, azo, alkylsulfonyl, and arylsulfonyl.
 19. The compound of claim 18, wherein saidsubstituent is alkyl.
 20. The compound of claim 19, wherein said alkylis unsubstituted.
 21. The compound of claim 19, wherein said alkyl ismethyl.
 22. The compound of claim 19, wherein said alkyl is substitutedwith one or more halogens.
 23. The compound of claim 18, wherein saidsubstituent is alkoxy and further wherein said alkoxy is methoxy. 24.The compound of claim 18, wherein said substituent is selected from thegroup consisting of alkylcarbonyl, arylcarbonyl, alkoxycarbonyl,aryloxycarbonyl, and amido.
 25. The compound of claim 1, wherein R⁷ isNR^(7c)C(═W′)WR^(7a).
 26. The compound of claim 25, wherein R⁹ ishydrogen.
 27. The compound of claim 26 wherein R^(7c) is hydrogen. 28.The compound of claim 26, wherein W′ is O.
 29. The compound of claim 26,wherein W′ is S.
 30. The compound of claim 28 or 29, wherein W isNR^(7b).
 31. The compound of claim 28 or 29, wherein W is O.
 32. Thecompound of claim 26, wherein R^(7a) is selected from the groupconsisting of alkyl, alkenyl, alkynyl and phenyl.
 33. The compound ofclaim 32, wherein R^(7a) is substituted or unsubstituted alkyl.
 34. Thecompound of claim 33, wherein said alkyl is substituted with an arylgroup.
 35. The compound of claim 32, wherein said phenyl is substitutedwith one or more substituents selected from the group consisting ofalkyl, alkenyl, alkynyl, aryl, alkoxy, aryloxy, alkylcarbonyl,arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, amido, halogen, nitro,azo, alkyl sulfonyl, and arylsulfonyl.
 36. The compound of claim 33,wherein said substituent is alkyl, alkoxy, or nitro.
 37. Apharmaceutical composition comprising a therapeutically effective amountof a substituted tetracycline compound and a pharmaceutically acceptablecarrier, wherein said substituted tetracycline is of the formula:

wherein: X is CR^(6′)R⁶; R² is hydrogen; R⁴ and R^(4′) are each alkyl;R^(2′), R³, R¹⁰, R¹¹ and R¹² are each hydrogen; R⁵ is hydrogen orhydroxyl; R⁶ and R^(6′) are each independently hydrogen or alkyl; R⁷ ishydrogen or NR^(7c)C(═W′)WR^(7a); R⁸ is hydrogen; R⁹ is hydrogen orNR^(9c)C(═Z′)ZR^(9a); Z is O; Z′ is O or S; R^(9a) is substituted alkyl,substituted or unsubstituted alkenyl, substituted or unsubstitutedalkynyl, substituted or unsubstituted alkoxy, substituted orunsubstituted arylsulfonyl, substituted or unsubstituted alkoxycarbonyl,substituted or unsubstituted arylcarbonyl, or substituted orunsubstituted phenyl; wherein said substituted alkyl is substituted withhalogen, amino, hydroxyl, alkoxy, alkylcarbonyloxy, alkyloxycarbonyl,arylcarbonyloxy, alkoxycarbonylamino, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, aminoalkyl, arylalkylcarbonyl, alkenylcarbonyl,alkoxycarbonyl, silyl, aminocarbonyl, alkylthiocarbonyl, phosphate,aralkyl, phosphonato, phosphinato, cyano, acylamino, amido, imino,sulfhydryl, alkylthio, sulfate, arylthio, thiocarboxylate,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro, cyano, azido,heterocyclyl, alkylaryl, aryl or heteroaryl; further wherein saidsubstituted alkenyl, substituted alkynyl, substituted alkoxy,substituted arylsulfonyl, substituted alkoxycarbonyl, substitutedarylcarbonyl, or substituted phenyl is substituted with halogen, amino,alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, alkylcarbonyloxy,alkyloxycarbonyl, arylcarbonyloxy, alkoxycarbonylamino,alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl,alkylaminoacarbonyl, arylalkyl aminocarbonyl, alkenylaminocarbonyl,alkylcarbonyl, arylcarbonyl, aminoalkyl, arylalkylcarbonyl,alkenylcarbonyl, alkoxycarbonyl, silyl, aminocarbonyl,alkylthiocarbonyl, phosphate, aralkyl, phosphonato, phosphinato, cyano,acylamino, amido, imino, sulfhydryl, alkylthio, sulfate, arylthio,thiocarboxylate, alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido,nitro, cyano, azido, heterocyclyl, alkylaryl, aryl or heteroaryl; R^(9c)is hydrogen; W is CR^(7d)R^(7e), NR^(7b) or O; W′ is O or S; R^(7a),R^(7b), R^(7c), R^(7d), and R^(7e) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, arylsulfonyl, alkoxycarbonyl,arylcarbonyl, alkylamino, phenyl or absent; or a pharmaceuticallyacceptable salt thereof, provided that R⁹ is not hydrogen when R⁷ ishydrogen.
 38. The compound of claim 1, wherein said compound is

or a pharmaceutically acceptable salt thereof.
 39. The compound of claim1, wherein said compound is

or a pharmaceutically acceptable salt thereof.
 40. The compound of claim1, wherein said compound is

or a pharmaceutically acceptable salt thereof.
 41. The compound of claim1, wherein said compound is

or a pharmaceutically acceptable salt thereof.
 42. The compound of claim1, wherein said compound is

or a pharmaceutically acceptable salt thereof.
 43. The compound of claim1, wherein said compound is doxycycline 9-carbamic acid 9H-fluoren-9-ylmethyl ester or a pharmaceutically acceptable salt thereof.
 44. Thecompound of claim 1, wherein said compound is FMOC 9-amino doxycyclineor a pharmaceutically acceptable salt thereof.
 45. The compound of claim1, wherein said compound is 9-(4′-fluorophenyl)doxycycline carbamate ora pharmaceutically acceptable salt thereof.
 46. The compound of claim 1,wherein said compound is 9-(4′-methoxyphenyl)doxycycline carbamate or apharmaceutically acceptable salt thereof.
 47. The compound of claim 1,wherein said compound is 9-(2′-bromoethyl)doxycycline carbamate or apharmaceutically acceptable salt thereof.
 48. The compound of claim 1,wherein said compound is 7-(4′-methylphenyl)sancycline carbamate or apharmaceutically acceptable salt thereof.
 49. The compound of claim 1,wherein said compound is doxycycline 7-carbamic acid 7H-fluoren-7-ylmethyl ester or a pharmaceutically acceptable salt thereof.
 50. Thecompound of claim 1, wherein said compound is7-(naphthyn-1-yl)doxycycline urea or a pharmaceutically acceptable saltthereof.
 51. The compound of claim 1, wherein said compound is7-(3-methyl-1-butyl)doxycycline urea or a pharmaceutically acceptablesalt thereof.
 52. The compound of claim 1, wherein said compound is7-phenyl doxycycline urea or a pharmaceutically acceptable salt thereof.53. The compound of claim 1, wherein said compound is 7-t-butyldoxycycline urea or a pharmaceutically acceptable salt thereof.
 54. Thecompound of claim 1, wherein said compound is 7-Fmoc amino doxycyclineor a pharmaceutically acceptable salt thereof.
 55. The compound of claim1, wherein said compound is7-(4′-chloro-2-trifluoromethylphenyl)doxycycline urea or apharmaceutically acceptable salt thereof.
 56. The compound of claim 1,wherein said compound is 7-(4′-fluorophenyl)doxycycline carbamate or apharmaceutically acceptable salt thereof.
 57. The compound of claim 1,wherein said compound is 7-(4′-methoxyphenyl)doxycycline carbamate or apharmaceutically acceptable salt thereof.
 58. The compound of claim 1,wherein said compound is 7-BOC amino doxycycline or a pharmaceuticallyacceptable salt thereof.
 59. The compound of claim 1, wherein saidcompound is 7-(naphthyn-1-yl)doxycycline thiourea 5-propanoic acid esteror a pharmaceutically acceptable salt thereof.
 60. The compound of claim1, wherein said compound is doxycycline 7-thiocarbamic acid7H-fluoren-7-yl methyl ester or a pharmaceutically acceptable saltthereof.
 61. The compound of claim 1, wherein said compound is7-(naphthyn-1-yl)doxycycline thiourea or a pharmaceutically acceptablesalt thereof.
 62. The compound of claim 1, wherein said compound is7-(3-methyl-1-butyl)doxycycline thiourea or a pharmaceuticallyacceptable salt thereof.
 63. The compound of claim 1, wherein saidcompound is 7-phenyl amino doxycycline thiourea or a pharmaceuticallyacceptable salt thereof.
 64. The compound of claim 1, wherein saidcompound is 7-t-butyl amino doxycycline thiourea or a pharmaceuticallyacceptable salt thereof.
 65. The compound of claim 1, wherein saidcompound is 7-(4′-chloro-2′-trifluoromethylphenyl)doxycycline thioureaor a pharmaceutically acceptable salt thereof.
 66. The compound of claim1, wherein said compound is 7-(4′-fluorophenyl)doxycycline thiocarbamateor a pharmaceutically acceptable salt thereof.
 67. The compound of claim1, wherein said compound is 7-(4′-methoxyphenyl)doxycyclinethiocarbamate or a pharmaceutically acceptable salt thereof.
 68. Thecompound of claim 1, wherein said compound is7-(naphthyn-1-yl)doxycycline urea 5-propanoic acid ester or apharmaceutically acceptable salt thereof.